The eye is on top of the pyramid and thus it can see all.
Meaning the entity on top of the pyramid is in the best position to make decisions for the rest of the hierarchy(pyramid).
Everything under the Capstone has the sole purpose of keeping the eye elevated to preserve it`s ability to see and thus make wise decisions for the rest of the hierarchy.
Who decides who becomes the capstone? Here we enter the realm/dimension of ideas.
"God"/The eye is the set of ideas that triumphs over all other sets of ideas in all possible hierarchies of ideas.