Although its appearance in "Duck Soup" is the best known instance, the concept of the mirror scene did not originate in this film. Harold Lloyd used essentially the same routine in his short "The Marathon" (1919). Max Linder included it in "Seven Years Bad Luck" (1921), where a man's servants have accidentally broken a mirror and attempt to hide the fact by imitating his actions in the mirror's frame. Charlie Chaplin used a similar joke in "The Floorwalker" (1916), though it did not involve a mirror.