This guy had left the restaurant to smoke his sigarette hiding in the doorway. Unfortunately he was under a reddish street lamp. He was amused at the idea of posing, but was quite pessimistic about the light. It is more visible on black
It makes for a very authentic image - smokers often give the impression of skulking to indulge their habit. It must make them feel a bit alienated - I think your portrait has caught this.