It seems to show both fear, anger and frustration.
One day I was watching two rabbits mating and the female sat in a corner so the male couldn't get behind her, he stood by the side stomping:lol: Poor Heffalump..(yup, that was his name)
I also once experienced as one student brought her dog into the rabbit-room at school, and the dog came over to look at the rabbits, a French lop spotted her, stomped, and suddenly all the rabbits started panicking:shock: