In the compound eye of invertebrates such as insects and crustaceans, the pseudopupil appears as a dark spot which moves across the eye as the animal is rotated. This occurs because the ommatidia that one observes “head-on” (along their optical axes) absorb the incident light, while those to one side reflect it. The pseudopupil therefore reveals which ommatidia are aligned with the axis along which the observer is viewing.

Honestly a more interesting answer than I was expecting. I thought it was going to be a similar thing to the fake eyes some animals have.

I do prefer people taking shoes off at the door.

I mean maybe. But one is a deterministic way to do the exact same thing, the other is a nondeterministic way to maybe do a similar thing.

Are you aware of the reason(s) for this? To discourage would be callers from following through?

You indicated you are against homogeny and pro discussion. I wonder how your proposed solution doesn’t contribute to these.