First off, this is a great song- fantastic to dance to! I love the concept of women being allowed to be themselves independent of judgment and feeling tied down to societal standards.
While listening to this song, I started thinking that the person MIKA is talking about might be a trans woman or a lesbian, someone who isn't always accepted as a woman. MIKA repeats "and that don't make her less of a girl" so many times that I'm thinking that there is a general lack of acceptance of this person as one. I was trying to think about why MIKA would write this song and thought that it might actually reflect how he isn't always accepted as a man since he is gay and he's portraying this through a song about a woman in a similar situation.
Just a bit of speculation. I'm interested if anyone concurs or has other ideas.