The empty throne · the aniconic Buddha

For roughly four hundred years Buddhist art did not depict the Buddha. At Bharhut and Sāñchī the crowds bow, the kings arrive, the elephants kneel — and at the centre of the scene there is an empty seat: a cushion, a footprint, a parasol above nothing. Scholars still argue whether this was prohibition, convention or doctrine drawn in stone; the effect is unmistakable either way.

The wing's namesake, and the whole comparison in one image.