WHY HELP GREMLINS?" poster
The pattern
This still is filed under Problem-agitate-solve.
Define
Name the problem, make the cost of leaving it felt, then present the way out as relief.
Mechanism
Tension then release. The offer is not an interruption. It is the only door once the cost of staying is clear.
Verdict
The problem is known but not yet urgent
Why it works
Takes a mundane, technical engineering instruction (rounding corners to prevent stress fractures) and makes it memorable through folklore and humor.
Steal this when
You need to communicate a boring technical rule in a highly memorable way.