Why is that?

From my experience, pictures taken at the normal human viewing height look uninteresting because they're taken at an angle we're most familiar with, which doesn't have much novelty.

Photos taken at unfamiliar angles will present their objects in ways we're not used to seeing. Which makes them less familiar and more stimulating. Which is more interesting.

I think this is correct. I'm a drone photographer and when drones became popular, you could take a photo from 50m up looking directly down of something plain like a beach and people would lose their minds. As that has become more common, further variations seem to capture more attention. I take a lot of photos from 3-5 metres up because most people don't walk around with ladders.

A good general principle in almost any photography is that if you want pictures that are different from everyone else's, just get down a bit. Most people take shots at their eye level and don't even think to try a different angle

Unusual points of view.

High, low, inside a pipe, from a tree, under water, where people don't usually go / aren't allowed / can't access, etc.

Keep in mind that the unusual can become commonplace if overused. Selfie sticks were initially a novel PoV. They became cliche in about a week.

If your pictures aren't interesting enough, you're not close enough

Counterexample:

https://en.wikipedia.org/wiki/Hubble_Deep_Field

Or up. The way I think of it is people looking at your photo shouldn’t know how tall you are.

I don't know the theory but I find these chicken photos more aesthetic than photos of chickens taken from above. It might have something to do with looking your subject in the eye...

maybe helps that project co creator is famous photographer https://en.m.wikipedia.org/wiki/Noah_Kalina

heard zuckerberg booked him as wedding photographer (for real)

Depth of field, quite literally here! Here are some rules of thumb: If you increase depth of scene, you can use depth of field in two ways. In portraits, you can create greater subject separation because the closer focal point of chicken will be in focus, but the horizon line will be very blurred. Taken at human eye-level, most of the background of a chicken will be grass that's close-by, and therefore a similar blurriness (or 'bokeh'). That makes it harder to discern subject.

Secondly, if you open up the depth of field with a very deep scene, you create more possibilities for composition, framing or storytelling. Again, all you have at human eye level is chicken/grass. At chicken eye level, with a very deep focal range, you might also be able to tell the story of the chicken in 'the great outdoors', you may see mountains and forests on the horizon etc.

Hope that helps.

Aside from angle it's taken from, which in itself makes a difference, this is also gives you a fighting chance to have the subject interact with you or your camera (or what it's hidden in) instead of having a very passive third party view.

This one for instance has near direct look into the camera, and there's no way you'd get that from human waist or eye level https://chicken.photos/20220611121718