That’s a Big Dog! A man holds up his Tibetan mastiff as they perform on stage during a dog beauty contest at an exhibition center in China on March About Tibetan mastiffs participated in the exhibition. - A nice, apartment-sized dog,
I see it could be two ways. One: the big dog is very kind and left the big bed for the pup. Two: the pup went on the big bed and left the small bed for the big dog. In that case, if I was the big dog, I would just lay on the small dog (or around it).