And if her performance in question did objectify her, or even degrade herself in some way, how is that a problem and who is it affecting? I don't see her personally-inflicted reduction of herself to a sexual object as a problem, because in the first place I did not expect, nor did I oblige MC to be some kind of "role model" for kids. It'd be an entirely different story if she posed as Hanna Montana and did the exact same thing, then kids and adults would have every right to complain, but I don't see that as the case here.
Anyways, the point I was making is that when you imply that a celebrity should be tied to some career choice for the sake of upholding some conceptual ideal, responsibility or duty obliged by society, that is objectification nonetheless; it's still reducing the celebrity to a thing that can be owned, dictated, and possessed as if they are a piece of public property--which they are not; the "thing" does not have to be sex-related in order to fall under the definition of objectification. She may be objectifying herself anyway, but even so, that doesn't automatically give other people the right to objectify her as well. She has a right to objectify herself because her body is her own property; but it is not ours.