I like the picture, but from a design perspective, I tend to see diagonals as indicative of action. Were you going for that here, as her face and body seem to convey the opposite... Also, from a composition standpoint, my eyes are drawn out of the picture by the staircase, though the horizontal piece brings me back in and to the model. I wish there'd have been a more solid connection that didn't take me out of the picture like that.
I have to say that I do like the symmetry of her legs and body paralleling the starway. Lighting is nice, she doesn't look like she's going to fall over, which is good. The blue behind her legs does a nice job of contrasting with her skin and making her legs pop.