Duck Soup

Trivia: The mirror sequence was filmed in only two hours.

Continuity mistake: At the gala scene at the beginning Groucho slides down wearing a black tuxedo. Not long afterwards he is suddenly wearing a gray suit jacket, and after his musical number it changes back to the black tuxedo.

More mistakes in Duck Soup

Rufus T. Firefly: Awfully decent of you to drop in today. Do you realise our army is facing disastrous defeat? What do you intend to do about it?
Chicolini: I've done it already.
Rufus T. Firefly: You've done what?
Chicolini: I've changed to the other side.
Rufus T. Firefly: So you're on the other side, eh? Well, what are you doing over here?
Chicolini: Well, the food is better over here.

More quotes from Duck Soup