When the barber is preparing to cut his hair, a close-up shot shows a chunk of cut hair on his right side. Then when the barber begins cutting, it's not there. But re-appears for the next close-up of him crying.
At the beginning of the movie, when Robert Ryan offers Dean Stockwell a hamburger "With or without" onions, it is initially one hamburger split in half. Then, when Stockwell grabs it, it is a whole burger, and so is the part that Ryan eats, rather than two halves.