Buster Keaton’s follow up to our Hospitality. He is very smart in setting up his gimmicks and choreography. You see him as one of the early progenitors of the farcical comic, using physical humor as part of the shtick. Keaton is inventing this alongside Chaplin. But more than Chaplin, he is inventing choreography of movement and stunts, whereas chaplin focuses less on stunts and has more of a storytelling bend that makes his gimmicks funny on a human interaction/personality level.
The use of double exposures, and frame within a frame, for the stunt of Buster Keaton entering into a movie screen shows the early technical innovations that needed to be accomplished to the lay the groundwork for later films as well as clichés of characters breaking the fourth wall within films, a scenario that Woody Allen would later use for Purple Rose of Cairo
Keaton was an innovator of film action/stunt effects.