This may also be how it works for humans. The more conscious parts of the brain are involved in coming up with a general "movement plan", while fine-grained re-balancing and re-planning is taken care or subconciously.
On the other hand, if you take another step back and think of the query input to the diffusion model, perhaps a text "human walking up to a higher floor" in our stair-climbing example, then you are absolutely right, that would be much closer to what we'd call "conscious" than I had ever imagined!
(my usual model of technical consciousness is an entirely different beast, the "simulate before act" approach with the additional requirement that the simulation includes a "self" and "peers" and the simulation includes rules/mechanisms that put them in the same category)