Bunnies like to rest their heads. My little guy likes to rest his head on my arm while he is sleeping on my lap. He also rests it on his stuffie, and his food bowl, and the side of his litter box. But his rear legs are weak. None of my other bunnies rest their heads on objects, and I read that bunnies with weak limbs feel more comfortable resting their heads on objects. It sounds like Nutmeg is just comfortable like that. But I would look at her rear legs. If she hops normally, doesn’t drag her limbs, doesn’t pivot, then she is just being extraordinarily cute.