(An obese Pinkie Pike? I'm joking...)
I could totally see her expression being a frown, because she disapproves of people looking at her in such form. Even now, her smile is hardly that. It reminds me of the Mona Lisa because you can not tell if she is really smiling or not. It looks like it, but not at the same time. The body is great here and... oh.... *explodes, shoes drop down to the floor.*