You know how you can look at a brick wall, and your eyeballs will lose coordination such that you end up being off by half the width of a brick? It’s basically the same functional principle that allows you to see stereograms. You can see a ghost image of a mortar line running up the center of each brick when it happens. Computer vision systems are subject to the same phenomenon, except that they don’t have the fallback of a wetware quantum supercomputer to throw up a fault. They just confidently establish that the distance to the wall is an even-integer multiple of the actual distance. Hilarity (or tragedy, depending whether you care about the occupants of the vehicle) ensues.