Can people see people at night with two layers of gauze curtains?

The two-layer gauze curtain allows people to be seen at night.

Gauze curtains that are light-proof and opaque are also effective at night, because after night, the lights in the house need to be turned on. At this time, if you look outside like a window, you will see the shadow of people. It is very clear, so if you close the gauze curtain, even if it cannot completely block it, you can see the shadow of the person, but it is not clear, it is just a vague shadow.