Kids may be intrigued by security mirrors that they see in stores, or cosmetic mirrors that enlarge their facial features. How do they work? Have kids note the respective convex and concave surfaces those mirrors. Then have them visualize that each point on the surface of the mirror is a separate mirror angled in a slightly different direction from its neighbors. In each of those point mirrors one will see an image of a slightly different part of the room or face. Integrated together the impression is a shrunken or image of the whole room, or an expanded image of a portion of your face.