The 13-year-old was made to sing a rendition of Cyndi Lauper's 'Time After Time', but was met with criticism for the panel for the "boring" choice.

Music mogul Simon Cowell told her: "I thought the song was boring. It just went on and on, so it's song choice. For some reason, Britney isn't quite getting the right songs for you."

Spears then defended her decision and explained to Cowell: "Simon, she has more talent in her pinky than all of your contestants together."

Following the show, Miller spoke to E! Online and admitted that her preferred genre of music definitely doesn't fit with what she's been performing on the programme:

"My song was really boring, and I've been telling Britney that from day one. She just said, 'Get through it and try to connect with the song'. I don't think it really mattered to her that I didn't like it."

"I don't really like slow songs. I listen to Nirvana and Radiohead, not really the divas."

Watch Miller's performance here:

This time last year, the well-known personality aired his concerns about the American version of the TV talent show, but it seems that its popularity has been far better than he could have ever predicted because he is now celebrating a new contract:

"I wanted you guys to be the first to know that FOX have confirmed that @TheXFactorUSA will be back next year for it's third season. It was important for you to be the first to know because it is thanks to your support and enthusiasm we are coming back."

"I want to personally thank each and every one of you, it is hugely appreciated and never forgotten. The live shows for this season are days away, I have a feeling, as we say in the UK, we are in for a complete ding dong! @TheXFactorUSA."

Mike Darnell, Fox's president of alternative entertainment, also praised the new judges in an additional statement: "This season, Simon [Cowell] and the producers of The X Factor took an already strong show and made it absolutely fantastic."

"The format changes are working, the contestants are unbelievably talented, and Britney and Demi - alongside Simon and LA [Reid] - have brought an incredibly fun new chemistry to the judges' panel that our fans really love. We feel great about the show and I'm thrilled to bring it back next year for season three."

The new pictures, which were uploaded to the programme's official Twitter page over the weekend, show the judging panel visibly enjoying themselves and even standing up in support of a performer on stage.

Britney Spears and Demi Lovato, the two new additions to this year's panel, seem to be getting along well with Simon Cowell and LA Reid, and former Disney starlet Lovato has even been joking with Cowell on social networking site Twitter:

"@simoncowell if you were a food you'd be crustaroni & cheese #xfactor"

'Hold It Against Me' songstress Spears also spoke out last week about how she felt "right at home" in her new role on the popular televised vocal talent show.

The show is currently without two judges and a host after Nicole Scherzinger, Paula Abdul and Steve Jones all left for pastures new.

There had been gossip that Glee's Darren Criss was being lined up to replace Jones as the show's host - but Cowell doesn't even know who he is.

When asked by Access Hollywood if there was any truth in the rumours, he replied:

"Darren Criss? I don't know who he is."

Cowell then proceeded to mistake Criss for co-star Kevin McHale. He added: "Is he the one in the wheelchair? I like him."

Speaking to the Evening Standard, Cowell explained that his self-set target of attracting 20 million viewers for the talent contest's debut series caused him a lot of stress and he wouldn't even celebrate the first episode's airing in case it bombed:

"I wasn't opening any champagne on the first day because now we had set everyone's expectations. The worse thing was in the second day because if you have a 30 or 40 per cent drop off, you're dead."

"And in fact somebody said to me, 'If this drops off 30 per cent Simon, it's probably going to be all over.' That is when I was tense."

Luckily for Cowell, the show has been a success and he has since relaxed about the initial pressure so can now enjoy the process:

"As much as people want you to succeed, there's a ton of people that want you to fail and I took a bit in the neck that first day. But I always trust the public and I get a feel for the show and it's been positive and starting to grow now."

Watch 14-year-old bootcamp star Rachel Crow perform a stunning rendition of Beyoncé's 'If I Were A Boy' below:

"We're not going to be making Syco porn movies, Not for the public viewing, anyway."

The music mogul also reveals that working with Susan Boyle taught him a duty of care:

"I learned that with Susan Boyle. I remember the day she came second and had that awful meltdown and I genuinely thought, 'Maybe we have failed here. Maybe we shouldn't be doing this.' But she wasn't a happy person."

The multi-millionaire isn't happy all the time either, and admits to have dark moods that "come out of nowhere" but doesn't approve of taking antidepressants but instead relies on friends to help him, one being his mentor, the Top Shop entrepreneur, Philip Green:

"What I was going through was just the inability to cope. I was trying to deal with everything - my business, the artists, the shows, everything - and didn't realise how difficult it was. He (Philip Green) is incredibly well-meaning. And very kind. He became someone I could always go to. He makes you confront everything and find a solution."

Cowell has also recently realised that he suffers from claustrophobia which is why he can't stand cluttered surfaces, and lives in huge airy houses: "I like the feeling that I'm never inside." he explains.

Watch Melanie Amaro's audition from this week's X Factor USA, and part of Cowell's interview with Pier Morgan on CNN below: 

Simon Cowell introduced his panel - Nicole Scherzinger, L.A. Reid and Paula Abdul - to the show and they all welcomed in the debut stateside season with both some unusual and incredible contestants. 

During the first show music mogul Cowell declared to 42-year-old Stacy Francis, "I've done this for a long long time, that was one of the best auditions I have ever heard in my entire life. Loved it, loved it, loved it. I love you."

In addition to her jaw-dropping audition, 13-year-old Rachel Crow blew the judges away with her energetic rendition of Duffy's 'Mercy' and Geo Godley decided to get the panel's attention by dropping his trousers mid-performance.

You can watch highlights from the opening episode of X Factor USA below and the second round of auditions will air tonight in America from 8pm CST.

The 'Straight Up' singer dropped in to The Today Show yesterday, September 20, to promote the talent contest which is due to premiere tonight in the USA and explained that Cowell has taught her how to grow:

"I've always known I'm a strong woman but he's really taught me some inner strength. He always provoked me and challenged me and the more I stood up for myself and the more I stood up to him the more he embraced me."

"We're like an old married couple without the sex - by choice! We get along so well. It took ten years to understand each other."

She admitted to host Ann Curry that she's so excited to be a part of X Factor USA and feels very at home working as both a judge and mentor, adding:

"This is a job where it's totally in my wheel house. I started my career behind the scenes mentoring and coaching and doing stage tours and helping create something very special."

"The X Factor is amazing because people say, "What is it?" I say that it's hard to articulate because it's not so tangible - it's what you witness when someone walks in and you know you're watching something very important and you're emotionally affected and connected with it."

Watch Abdul talk about what to expect from the debut season of X Factor USA below:

Appearing as a guest on Piers Morgan's CNN show, the music mogul explained that Cole seemed out of place as a judge alongside himself, L.A. Reid and Paula Abdul:

"I was talking to someone about this at the screening the other night and they put it very well - she looked a bit bewildered."

"Not everyone's like you Piers. You come to a country like America, it's a bit deal, takes a while to adjust," he joked. "And I took the view, along with a few other people, that she would have been more comfortable back in the UK."

He also added that because Cole's departure was in the public eye he feels as though he has to "take full responsibility for it" and be the bad guy:

"Because it was public, of course. I think if she'd taken the UK gig, nobody would be feeling bad right now, because they're both big shows and hopefully this one will be as big as the UK show."

"But that's what you have to do when you produce, you have to make decisions in the moment and I take full responsibility for it."

CNN International will air Cowell's interview tonight, September 21, at 9pm BST and you can watch him talk about the debut series of X Factor USA, which also premieres in America this evening, here: