paragraph: You have seen your own reflection in a mirror. The person looking back at you looks just like you. Where does that reflected person appear to be standing? Yes, they appear to be on the other side of the mirror. That is really strange to think about, but very cool. Have you ever waved at your reflection in a mirror? The reflected image will wave back at you. Here is something to try next time you stand in front of a mirror. Wave to your reflection with your right hand. What hand do you think the reflection will wave back with? The same hand? A different hand? You will notice something interesting. The reflection waves back with the hand on the same side as you, but it is their left hand. The image in a reflection is reversed. This is just like the image of the sign above. Light rays strike flat shiny surfaces and are reflected. The reflections are reversed. 
question: How does reflection work?
answer: The image in a reflection comes from the lights