I like the composition of this a lot, though if it were possible to back out a little and get the bucket in the shot that might have added something. I'd imagine that would have introduced a bunch of clutter from the background though, so cropping it like this was probably a good choice. Frankly, I think the lighting is terrible in terms of the reflections on the bottom of the arm, and the evidence of the light that has been cropped out in the lower left. The direction of the lighting is pretty good though. The colouring seems a little off, and I'm not sure if that's just because of the nature of the lighting and the fact that it is a night shot, or if has to do with the post processing. I would try it in black and white, as that is an easy way to take care of the strange colour casts you sometimes get in night shots (from sodium vapour lamps or whatever the hell they are).