In A Dog's Life, during the lengthy dance hall scene, there is a sequence where Chaplin is on the dance floor, the titular dog on a flimsy leash behind him; at one point, the dog stops, and stares off-screen--at a crew member, or possibly its owner, clearly looking for approval. The moment is short, but disarming--not because it subverts the fictional nature of the film, but because that moment we realize how little a movie means to a dog: the dog, however well trained, does not realize what a camera is or why it's being filmed.
So is it still cinema if the subject in unaware that they are being filmed? Or do "hidden camera" films constitute a different form of expression altogether--the more I watch movies, the more I realize how essential the relationship between the subject and the camera and microphones (the audience's eyes and ears) is. The dog is incapable of completing this relationship--it becomes "a part of the landscape," a true non-actor.
The Idle Class finds Chaplin and leading lady Edna Purviance playing rich people named Charles and Edna. But it's a double role for Chaplin, as he also appears as the Tramp, and a case of mistaken identity leads Edna (Charles' wife) to flirt with the Tramp at a a costume party.
How is Chaplin both the Tramp and the rich man? How is he able to parody himself (a rich man with marital problems) while remaining a different character, a yet be instantly identifiable with both? It's Chaplin's greatest strength--that the concept of Chaplin can be identified with both the innocent Tramp and Monsieur Verdoux, with the tragic clown of Limelight and the farsical demagogue of The Great Dictator. The real Chaplin, like the characters in The Idle Class, was both the symbol of Hollywood glamour and a working class hero. It is a conception of identity that only the cinema could have invented.