Uhh, because of the heat of the raspberry pi & camera behind there

Suppose you were in this situation and suspected something. I’d imagine the space behind it would be totally dark, so what would be a safe way to check if there’s a gap in between without breaking the glass?

there are no “one-way” mirrors. You just need to make your side darker than the other side (there’s a reason the observation side of a two-way mirror is never brightly lit, but the interrogation room is)

Tldr: put your face right up against it and use your hands to block out as much light as you can