Another Disney camera pull-back opens the Silly Symphony Frolicking Fish (1930). The purpose of the cartoon seems to have been to impress people with how many bubbles could be animated. They’re all over the place in this cartoon. The camera finally reveals the bubbles are coming from a happy fish, who eventually turns and swims out of the cartoon.
Disneyshort.org says ten animators worked on this. With all those bubbles, it’s no wonder.