adamconover answered:
Booth is a legendary cartoonist who can do whatever he wants. There’s no “joke” - it’s just a funny scene straight from the cartoonist’s id.
kevincorrigan answered:
It’s a joke, duh. For chuckles.
tpuppets answered:
I wondered whether it was referencing something, and I found an Earle Slabodne on facebook, and his picture only complicates matters.