To Joe's comment, yes, he's very much at peace. He lives down below and walks up here often just to sit and watch the city. He said the fireflies are out right now and the sight is quite lovely. Very nice gentleman - he gave me a tour of the area and walked back down with me to show me the path. (The way up is either via the same steep path, or by "train" - more info here.)
What strikes me here is balance, created by the light & dark areas and horizontal & vertical lines. But there is nothing to balance your subject, which brings my eye straight to him.
nice shot, the comp and tones are great. i like how he's watching the space together with his lonesome telescope friend ;)
he seems to have a camera sitting next to him, too?