Symbolism
Through out the movie there are sly little "Easter Eggs" of symbolism. A few examples, Fran's shadow walking ahead of him when he's cutting through the alley (getting ahead of himself) and the smoke stack blowing steam above his head in the hobo camp when he's beating up the other bum. He's literally "blowing his stack".
Can anyone name some others?
If my answers frighten you then you should cease asking scary questions.