The mayor shown throwing out the first ball was a caricature of then-New York City mayor Fiorello LaGuardia.
The 1940 World Series was played between the Cincinnati Reds and Detroit Tigers. The Reds won, 4 games to 3.
Although the game is ostensibly being played on the East Coast (Yank 'Em Stadium=Yankee Stadium), the radio call sign, KWB, indicates a western station. K is used in the west, W in the east. WB being short for Warner Brothers, of course.
According to the date on the newspaper, the game is being played on August 20, 1940.
Baseball Bugs (1946) reused several of the sight gags shown here, including the screaming screamer ball.