the shadow in the rib kills it for me! take anothe body shot without the shadow lighten up the body and leave the rest daark and you have yourself a picture!
actually i wouldent make it brighter.
i think if you leave the shadow across your ribs and darken everything below it so only the shoulder and back are lit up it would look awsome. darken that right arm and everything below the left elbow and i bet you have a winner.
if you leave it as is i think the hand is distracting.. unnatural looking. whats in it? a lens cap?