What does it mean when a rabbit grooms its inside of their hutch?

just about the question above, my rabbit had a companion, but sadly its companion snowball had to get put to sleep as she had cancer in her lungs. i was just wondering is it because she misses grooming things, but we have put a cuddly toy in for her she loves to groom that, she also grooms our dressing gowns, but she would never do that when snowball was with her. please help i dont think it is serious though. thanks :)