Nice exposure for a portrait. It has the normal range of tones one would expect to see. In a low key portrait the shadows would be more pronounced, deeper, moodier, with the highlights creating the form of the face. Sorta just the opposite of this.
Not too bad a portrait but not that low-key, very heavy on mid-tones. Also, DOF seem TOO small for me, with one eye sharply in focus but the other a bit off.