As Betty falls down the "rabbit hole" in the subway, the mass of jam that she pulls out of the jam jar morphs into a caricature of Ed Wynn. 17 years later, Wynn voiced the Mad Hatter in Disney's "Alice in Wonderland."
Loosely based on "Alice's Adventures in Wonderland" and "Through the Looking Glass" by Lewis Carroll. In particular, the visuals seem to be based on the film adaptation of Alice in Wonderland (1933) also by Paramount Studios.
When Betty dozes off, the clock shows about 10:07. When she wakes up, it's 11. So her one-reel adventure lasted over 50 minutes.
The characters Mad Hatter, Mock Turtle, Gryphon and Carpenter are modeled quite closely on the John Tenniel illustrations made for the first publications of Lewis Carroll's Alice in Wonderland and Through the Looking-Glass.
The White Rabbit uses the Shave and a Haircut, Two Bits knock to get into the mirror.