Factual error: At the beginning of the episode, Dorothy tries to turn off the dirty video that Sophia rented. She presses the fast-forward button on the VCR remote by mistake, and the music on the television continues at a faster pace. However, most if not all VHS players (in the 1980s and today) do not play audio whilst fast-forwarding or rewinding.
Revealing mistake: In the opening scene, the girls are watching a movie on a VCR. As the camera pans across the back of the TV and VCR, you can see that there are no cables connecting them.
Answer: Ice makers were a new invention, advertisement purposes.