Careless talk costs lives" poster
The pattern
This still is filed under Negative headline.
Define
The first line is a warning, a refusal, or a negated claim. Something the reader cannot skim as praise.
Mechanism
Pattern interrupt. A negative is harder to slide past than a compliment. The payload must arrive immediately after the stop.
Verdict
The category is full of sunny claims
Why it works
It takes a very literal interpretation of the message (taping a mouth shut) and combines it with a high-contrast, explosive graphic design that makes the warning instantaneous and unmistakable.
Steal this when
You have a simple, singular behavioral rule to enforce and need maximum visual impact.