Study in Light and Shade

This is the first time I've attempted something like this. Please

provide constructive criticism. Thanks.

A good experiment. I have 3 suggestions - (1) choice of background - if it was more uniform, it would have been better (2) there are some reflections of light in the white glass background - is it due to flash? If you have used flash, I will suggest to take the shot without flash (3) make it a B&W shot