Charlie Chaplin imitates Adolf Hitler. This is high art. It is almost ballet, and is full of symbolism, like Hitler kicking the world:
Charlie Chaplin - in a plane
Overall, the movie was mostly slapstick, not that different from a 3 Stooges film, until the great ending. A Jewish barber who looks like "The Great Dictator" ends up impersonating him though a series of unlikely events. This final scene elevates the movie.