People started publishing a photo from the scene, showing a forlorn schoolbag and books.
A photo was found of Arab Jerusalem activist Muhammad Abu al-Hames - with the props.
You can see him with the schoolbag,a bulletin board and bags of other materials.
Here's a closeup of the bulletin board in the debris that you can see matches what al-Hames has in pristine, clean condition.
(h/t Abu Ali Express)
UPDATE: More of the bulletin board. Note how it was cleaner with al-Hames then when it was in the rubble, so he didn't "save" it.