The Masquerader is clearly another attempt to show a comedy behind-the-scenes at the Keystone Studios (identified as such within the movie). Chaplin has brief scenes with his Keystone peers Roscoe Arbuckle (very funny) and Chester Conklin (middling).
This is also one of only three times in which Chaplin impersonated a woman on-screen. The premise is that Chaplin is fired from the studio by a director (Charles Murray) who dislikes him. So the next day, Chaplin returns to the studio in drag (a title identifies him in get-up as “a fairy”!).
There are some lovely comic opportunities here that go explored only about halfway. First off, Chaplin makes his initial appearance as Chaplin; he changes into his Tramp costume a few minutes into the film. So for once, we’re expected to accept Chaplin on the screen as Chaplin, even though he is put through the usual “Charlie-esque” paces.
Second, this movie is the second of Chaplin’s three on-screen female impersonations, and it certainly fits right in the middle. Unlike A Busy Day, where he hammed it up as a broad, and the later Essanay A Woman, where he’s a startlingly convincing female, here he does almost nothing with the gimmick, perhaps because of the one-reel time constriction. Pity that such a fertile idea wasn’t allowed to run its course, while an arse-kicking fest such as The Property Man was allowed two whole reels.