I am impressed with this photo. The light and colour is spot on. I love the expression. The top half of the photo was executed beautifully.
One minor point (issue?) in my opinion is the arms. The cropping on the model's left wrist, as well as the positioning of the hands. I feel that the hands are a little awkward; at times they add more to the portrait, but looking again I feel it takes away from the top half. I'm a little torn by it, which could be a good or a bad thing. At the very least, the bottom half does add more interest to the scene, elevating it from the standard shoulders-up portrait shot.