The mouse is made to fit in the palm of your hard. Rest your hand on the rounded top, and push. You will see how the pointer on your screen moves around. It works similar to the game you find in fairs, supermarkets, deparment stores, where all of the toys are inside the glass case. You have to manuever the claw to pick up the toy inside the case. Since you cannot reach your hand inside the case, you must use the tool, by manuevering the lever.
Oh dear, I bet that in a few decades, we'll all need videos like that.