Whoa: it's that poster. I've seen it in WW2 collections, adn here it is in an ad. Meta meta.

"Here's something we can talk about, Hank! This poster! Some say the stifling hand of Uncle Sam is engaged in censorship, but most of us understand it's a comic description of what the ol' fictional embodiment of our Ethyl-producing nation would want to do if some one was blabbing about the invasion plans.

"Between you and me, I hear it's on for June, in Normandy."