I don’t think it’s that simple. For the egg carton your eye will not spend almost any time looking at its top. You will spend most of the time sampling the bottom. I don’t know what we do, but it does not feel like a naive grid search.

I really don't think you have the ability to use self-reflection to discern an algorithm that occurs in your unconscious visual cortex in a split second. You wouldn't feel like you were doing a naive grid search even if a naive grid search is exactly what you were doing.

You have suggested that the process in your mind to find a global minimum is immediate, apparently to contrast this with a standard computational algorithm. But such comparison fails. I don't know whether you mean "with few computational steps" or "in very little time"; the former is not knowable to you; the latter is not relevant since the hardware is not the same.