bitter look

This is a fine, fine portrait. Everything about it, from the foreground to the background, from the wrinkled flesh mimicked by the stripes on his collar, is Just Right. You're off to a very good start. My only criticism is the title. Personally, I don't see "bitter" here. I think it would be nice not to try to explain the expression on his face to people and let them come to their own conclusions. It's a complex face, which is good, and you should not try to simplify it with a single adjective when so many might be applied here.

Good work.