There is a lot of image degradation in the 'white' areas. I'm guessing that is from JPEG compression...but what ever it is, it doens't look good.
Other than that, I like the subtle lighting on the subject. I'm not sold on the crop, it feels too tight, but I don't hate it either.
I'm not sure what you were going for, for the background...it's just sort of grey. Did you want it to be white?