These structures & processes can take the form of designed objects, certainly, but they can also be more abstract, like methods, procedures, perspectives, patterns.
Often a prompt built into the mechanics is not so much a direct provocation -- though it can be that -- as much as it is an opportunity or an affordance. Frex: drawing a card & answering one question in Quiet Year is a pretty direct prompt. But an MC or player-side move in AW is more like an opportunity -- inviting you to pick it.