Behold, a Speedball lettering guide's some suggestions for Movie Slides - pictures they showed on the screen before the fun started. I found it on archive.org, where it was dated 1927. That might be correct. But nothing is fully formed or springs out of nowhere, so you're looking at mid-20s culture here. For all its concerns about the Rise of the Machine and the mechanization of life, it was still a hand-drawn world.