Because she's in Germany and that's just what you do when you're in Germany- follow the local customs. Duh.
Maybe it's just a dance move. (ETA: Actually, I think she's holding the mike to the audience... or something.) Or else she's trying to be provocative. I'm shocked. Like, really.
Anyway, notice how she wears gloves all the time now? Her hands are the only part of her body that's showing her real age.