I just read some comments of this painting at a site and some girls were talking about they see themselves physically at the mirror. Of course the weight problem was raised.
It was a surprise for me because I remember looking at this painting when I was a girl and never thought about physical details.
She seems to be asking questions that will be with her for the rest of her life, those questions that has to do with our existential doubts, the way we conduct our lives, the incertitude, fears and emotions.
Her hands are at the mirror and I take it as a sign that we have to embrace all these questions that will never cease or which answers will always change and keep trying to do our best.
Have a great Saturday.