Don't gum up a book
The pattern
This still is filed under Image carries the claim.
Define
One image does the entire argument. Copy, if any, is a caption, not a second ad.
Mechanism
Pictorial claim. The picture is readable as a sentence. If we need a paragraph, we picked the wrong picture.
Verdict
The idea is visual and the surface is a poster, a feed, or a silent frame.
Why it works
The headline is a pun that runs two meanings at once: literal gum on the pages and the idiom for ruining something. The typography enacts the message instead of describing it, because 'GUM UP' is drawn with stretched, stringy, dripping edges, so the words look like the substance they warn about. Everything else is stripped to silhouette, which is partly a three-colour silkscreen constraint and partly a hierarchy decision: the only white shapes on the sheet are the gum strings and the headline, so the eye is forced from the mouth to the word. Prohibition posters usually explain a rule; this one shows the damage in one frame and lets the reader supply the reason.
Steal this when
When one specific behaviour has to stop in a shared space and you have no room for explanation or enforcement. Also when a piece of slang has a literal reading you can draw, so the type can do the arguing.