An imperfect composition, a rather dark or bright image, and less than ideal conditions could be ingredients for a great image.
His Instagram account is one of my favorites. It may not be everyone's cup of tea at first glance, but if you read his FAQ you'll see what his goal is for his photography. He writes:
I'm not trying to reproduce reality. Every image I make is an attempt at expressing myself and showing what that place, object, whatever, means to me.
I believe his images do exactly that.