To make this lesson work, you begin by setting up the "skinny fish tank" with water and corn syrup or sugar. Then you go through the "paper and pencil" lesson about the optics of mirages, and why they are perceived as bodies of water. Then it's time to hit the tank with the lasers to see how the index gradient causes the beam to curve. By then, the connection between curving light rays and mirages is understood.
Examples of inferior and superior images are included in the instructional presentation.