 FACT: In the bomb shelter, the father sets up a mock television with  a film projector and a rear projection screen. He makes a point of  saying that it uses a mirror, and the image (an episode of "The  Honeymooners") is shown reversed. However, with that setup (which  was relatively common back in the 1970s) the image would be normal,  not reversed, because viewing through the rear screen is the second  reversal.