Corn, the food of the nation" poster
The pattern
This still is filed under Civilian war-duty equate.
Define
A civilian act (saving, making, staying quiet) is framed as the same duty as the front.
Mechanism
Moral equate. The small act inherits the gravity of the large one. The ask is ordinary. The meaning is not.
Verdict
We need mass compliance on an unglamorous behavior and can honestly tie it to a shared stake.
Why it works
Instead of focusing on what people *can't* eat (wheat), it enthusiastically sells a substitute (corn). The imagery provides visual proof of how versatile and appetizing the alternatives are.
Steal this when
You are taking something away from your customer and need to vigorously sell the substitute as an upgrade rather than a compromise.