Four Indie Comics Variant Covers for ‘The New Yorker’

Indie comics creators like Chris Ware, Adrian Tomine, Ivan Brunetti, and Dan Clowes are no strangers to "The New Yorker" magazine, but for the upcoming 85th anniversary edition of the magazine they're all going to be illustrating variant covers, comic book style. There's also apparently a "secret message" encoded in the covers. Can anyone decipher it?