What parts of your picture should move?
3
More about the lever mechanism
A difficulty often encountered with card levers is that they become creased and lose their stiffness. In such a case when you pull or push on the lever, it bends at the point of creasing rather than turning about the pivot point. You can prevent this happening to some extent by using corrugated card for the lever.
Ensure that the corrugations run along the length of the lever.
If you don't have any corrugated card, then you can achieve this effect by sticking drinking straws along the length of the lever. Both these approaches will make it more difficult to push the paper fastener through the lever.