When the Emperor and Curlycue (in drag) are both being nipped by the crab during dinner, Larrycus and Mohicus are standing behind them. Their relative positions change a few times.
When Curlycue initially makes the sandwich with the crab and raises it to take a bite, he is holding it so that both the crab and loaf are upside-down. However, when it switches to the closeup and the follow-up shot, both the crab and loaf are now right-side-up.
Larrycus uses a cigarette lighter, and the Emperor wears glasses. Both were unknown in ancient times.
Corrections: the cigarette lighter and eye glasses were not bloopers. They were intentional anachronisms to accentuate the absurdity of the Stooges.
As the guards chase after Larrycus, Mohicus, and Curlycue, after pulling the rug, one guard knocks over a chair.