All rabbits do that out of necessity.
The pellets you see it eating are not technically feces.
They’re special ‘pellets’ the rabbit produces to maximize digestion of certain nutrients that they cannot obtain, otherwise.
If a rabbit is placed in a pen where all the droppings fall through the screen and it cannot eat these pellets, it will die.
Actually, it’s not the little pellets that they eat, it’s the cecotropes (wet and nasty stuff) that they eat directly from the anus. Yummy!