The Irish origin of the "One dog goes one way and the other goes the other" painting in the movie 'Goodfellas'. The painting was by Goodfellas co-writer Nicholas Pileggi’s mother. It was a recreation of a photo of a man named John Weaving who lived on a houseboat on the River Shannon. The photo was published in November 1978 by National Geographic Magazine. It was a feature about the Shannon and the people and places along its banks.
The dialogue in the scene is great:
TOMMY: I like this one. One dog goes one way and the other goes the other.
MOTHER: One’s going east, the other’s going west. So what?
TOMMY: And this guy’s saying, “Whaddya want from me?” The guy’s got a nice head of white hair. Beautiful. The dog it looks the same.