https://www.homestuck.com/images/storyfiles/hs2/00019_1.gif
https://www.homestuck.com/images/storyfiles/hs2/00019_2.gif
You use the HAMMER, NAILS, and POSTER on the blank space on the wall.
It's glorious. Exactly what you wanted. The old man really came through this time.
John: nail mother against wall.