In a twist on the usual ‘ID this and that’-threads, I can’t give you any other clues than what I remember from the poster:
A silhouetted man, standing before a black backdrop, with a gun pointing into the lower right corner. That’s about it. The film is probably a sort of black comedy, or at least sort of black. It may centre on a hitman, and I seem to remember something with ‘dog’ in the title. It might not be an American film. It’s probably something with a sort of ‘cult’ status among a certain subset of movie goers.
Yeah, it’s not much, but I’ve seen songs identified by descriptions like ‘the chorus goes something like ‘da da daaa da da dadaaa’…’, so I’m giving it a shot.