Glue the side of the Observer on with more Hot Glue. To give easy access to the inside, tape the top onto the box instead of glue (Shown below).
And you are done! Invide some friends over and facinate them with your own selfie machine!
Make sure you enabled the camera and that it is plugged in. If the problem persists, restart your Pi.
Make sure that the button is plugged in correctly, and that the scipt is running.