Overall, this is clearly a good picture, a cool, calm character just chillin out, but oh-something's caught their eye. You can definately see life in his eyes, and a real effort at that :]
Anatomically speaking, it's perfect, a slender physique is allways difficult to get in proportion, so that's great
The one thing I feel like this picture is lacking is the impact.
There's no clear OOMPH!, perhaps darker shadows or a more complimenting background would bring it out a little more :]
But I like the way you still showed his eyes despite the hair
Overall it's a great picture