Why is the reflector also called rice pineapple?

The earliest white foam board was nicknamed rice pineapple, which was like pineapple skin and rice. At the earliest, there was no such thing as reflective cloth. Foam board was light and white, suitable for fixing in various places. So when you need to reflect light, you will say, "There is a pineapple in that direction." Later, with the metal-coated cloth reflector, the foam board was basically eliminated, but many people still used to call the reflected light rice pineapple, which is a memory of the past.