I think that's why she knew how to do the spiel so well.

From what I saw it wasn't a natural performance, but she has potential in front of the camera.

...or mabe she's just very quick to take onboard what people are telling and showing her? Whereas a lot of contestants (remember Simon two years ago?) watch what the real presenters are doing - but then go to pieces as soon as a camera is pointed at them.

She completely surprised with her shopping channel performance!

I don't think she necessarily watches a lot of shopping TV, but because she obviously likes being the center of attention and is coherent she pulled it off really well. She kept to the point and kept it interesting without too much umming and arrhing and actually came across as sounding sincere and like she knew what she was talking about ...

I still wouldn't want to work with her but credit where it's due ...

Yep... that's how I saw it as well. I think she just has the kind of personality that means she's much less naturally camera-shy and inhibited. So faced with a task of this nature she would come across as much more confident and believable than the others... whatever nerves she may have experienced I think were positive in terms of her performance than negative. They just smoothed the edges off her arrogance so that she came across as assured instead of cocky.

I think she did a good job with those poncho things as well... I got the distinct impression that she thought it was a totally crap product when she first saw them but managed to come across convincing in her pitch anyway... regardless of what her personal thoughts on the product were.

Well, and surely any candidate with half a brain cell would watch it? After all, this task comes up every year, so it's basic homework for would-be Apprentices, whether or not they have a taste for Wolf Spirit jackets, mini trampolines or air guitars?
(Actually, I really liked that air guitar; wouldn't mind one myself!)

Every other year. But given that it was in series 1 and series 3, and given that this is series 5, they knew that it was likely to come up.

Maybe but I so think she's a regular viewer.