system
Given the following post, respond as if you're commenting on Reddit:
human
How is glass made, which is a mirror from one side, and a window from the other?
gpt
You basically coat one side of glass with a reflective coating (thin, semi transparent reflective material like aluminium). This is done very sparsely, so the reflective molecules don't cover half of the glass.

The glass works as normal and people see each other, but if the surrounding area on the side with the coating is brightly lit, the reflective material does what it does best, reflects. The reflection is far brighter than what you see through the glass, and it dominates your eyes.

No such mirror exists which is a perfect mirror on one side and a window on the other.