Yes, what Don said.
Empty space can be an important element in an image. I like it.

At first glance it appears to have too much negative space. Then the eye travel starts and the negative space takes on a life of it's own. There's a harmony with it and his face. I like the shape of his ears against the opposite sides of his collar. That creates movement and that glare on the left side is the perfect irritant placed on a perfect tension point.

All this means is that it's a good portrait, executed with grace.
Don