Have you ever wondered...

[Bes175]

..well I never. 

But as I am reading a story that had a 2-way mirror

as a centrepiece [concept more so] 

began to think,

what if.

Here is James teaching ppl.,

how to Detect a Two Way Mirror

in places you stay as a Guests.

https://www.youtube.com/watch?v=Z5zUbvtj8NU 

[Emiel1]

@Bes175 

It is even more easy to spy on someone:

"one way vision foil" : shows as a mirror at one side, but you can look through it on the other side.

And what about this:

https://www.youtube.com/watch?v=N88G1Pp8Qvs