When Alizée began, she was a teenage girl. Now, she's a few years away from 30. (
(A smile is required when you point out that a woman is almost 30.) (An even bigger one when she's almost 40, but that can wait.) All grown up!
She has to find herself, find who she is musically and as a performer. Now, it's obvious that UEDS was a false start as far as commercial viability is concerned, and she's just as aware of that as everyone else if not more so. She'll be doing something different with the next album, by the rumors a return to her pop roots, which is probably a good idea, but remember that doesn't mean she'll be doing the same sort of thing as in the early 2000s because she CAN'T.
So of course she has to change -- well, has changed as a person, and as a performer she has to change, too.