the dichotomy is the obvious one: inside and outside. But the *title* puts a sardonic twist on it, by designating the inside as a non-smoking area and the outside as a smoking area...
more like modern conversations to me. you know, the kind where one person is wanting to have an intimate talk with someone, but the other person has their cell, and a newspaper and is constantly looking around for interesting activities to divert them.
lovely, dramatic lighting (or lack thereof)
the silhouette and shadows of the chairs and the closed door of the dark eatery gives this photo a sort of calm, peaceful feel - which contrasts starkly with the busy road (passing cars) outside.
Its a stretch imo but okay. Technically I would crop some of the black space out of the bottom of this shot and would have waited til the car passed. The way it is my eyes are drawn to the car and what's outside the door not the table with the ashtray and the ones without.
Sorry, I don't get it. Is it that the ashtray is on one table and not the others? Did you mean to have the outside car the main focus of your image? I think more of the chairs are your main subject.