Before leaving his guest bedroom to go to the lighthouse to investigate its light being on, Jimmy pulls the bedding down off the pillow. When he returns a few minutes later, the bedding is back to its original state, over the pillow.
Three different lighthouses are shown instead of one.
You can see shadows of the actors on the backgrounds outside of the house.
Superman tells the ship's officer that he hears Jimmy in trouble, but Jimmy was unconscious at the time.