First off, technically, I think it's about impossible to hide your face using your cellphone. In the case of Vanessa Hudgens, she's generally done more exposing than hiding when it comes to iPhone usage. I'm still not quite sure why such a hot young actress would want to hide herself in the first place.
That sweet mug of hers is part of the reason she has a successful career, that delicious body in shorts and boots is the other part. I'm sure there's some small percentage for acting and singing talent as well. But why hide your greatest assets, ever? Vanessa, I'd know your belly button piercing from ten miles away. Quit with the cellphone thing already. Enjoy.