So our own Rob Neyer was poking around the Branch Rickey file at the Library of Congress when he came upon a memo the Mahatma had written in his days with the Cardinals. This is the letterhead, containing an early version of the Cardinals' famous birds-on-bat logo:
It struck me immediately that one of the cardinals appears to be talking to the other while the other is copping a bit of an attitude.
Given this and the type of artwork used, I thought it very much suggested a New Yorker cartoon of the period. That inspired me to make it so, probably also inspired by a Flintstones bit dredged from the mucky depths of my mind: