Well... you've got a lot of good things going on here. The setting is appropriate for the subject and without any distracting characteristics. The pose, though simple, is pretty good. And the lighting is close too. I feel it might have been improved if some of the main light was falling on his right cheek. You'd likely get a bit of light in his right eye too doing that. Of course, you'd have to turn him since you can't move your light source.