Amazing work. Negative space at the bottom left helps guide the eye to the subject. The way the prop is positioned with a slight angle adds to the photograph by making the pose looking natural and original at the same time. I also like the expression on the models face.
The pastel palette also works well, by giving it a dreamy look and kind of blending the blue background with the white prop and then the brown tan color of the model. It draws to the hair and face that has more detail.
The lighting is also done well. The main light highlights the body and causes shadows at the right places. Also the fill light gives it kind of a 3d look.