For me, this photograph was all about contrast: the contrast of his skin against the black background and his clothing, the contrast between the absolute dark of where this man is standing and the blurred light of what he is looking at.
I think the most powerful contrast would be that of his reflected self [the expression it holds] and his actual self. While the man in the window seems almost angry [which reminds me of a ghost or a past self], 'the real man' looks thoughtful or maybe a bit sad.
The photographer did an impressive job in capturing a moment in the life of this man and the two sides that could be interpreted from this moment.
Though I have seen this photograph a few times before [hence the rating for the originality category], I had not seen it photographed this well. Overall, this picture is really quite powerful and well captured.