Other mistake: When Alfredo projects the movie through the window on the facade on the far side of the piazza, the picture could not be as well-focused as we see it. Besides, there would not be a picture on the theater screen (at best a very faint one), resulting in a mayhem in the audience.
Other mistake: In a brief scene we see Toto, as a young projectionist, in the projection room rewinding one reel of film by hand from the used [A projected] reel onto a new [B ready to be projected] reel. However, the film is being rewound from A to B in a straight line. This is incorrect. The film has to be rewound top to bottom like a figure 8, if not, it will be projected with a reversed image. Of course, it has to be rewound, if not, the film would be projected from end to beginning.