She was upside down, rolling on the floor, fighting with a dog toy. And, I was not sure who was winning. She would bite and shake it then suddenly roll over as if the toy had thrown her on her back and she was fighting off an aggressive enemy. Like a child, having an invisible friend, my guess was this was her way of saying, "Fine, I'll go play my own game!"
Well, if nothing else, she can entertain herself.