This section of mirror doesn't fog

Your part of a TV show!

It's heated.

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

Ah yes, 10W of heat :3
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
- I read a long time ago that putting something flat against the mirror will show you. I think if the mirror is legit you’ll see the reflection directly on the surface, if it’s two way the reflection will look like it’s inside the glass.
  But I’ve never had the chance to actually test that, so take it with a grain of salt.
  Edit: Turns out this is incorrect; thanks to everyone for educating me!
Ahh yes, because that would produce exactly square shaped heat.
- Big camera.
- Why else would it be called the inverse square law?
  Gets rid of fog
  is in shape of a square
  Makes sense to me!
- It a very big Pi. Might even be a Tau.
- Lol, when I cut a hole in the wall I always make it the exact shape of a raspberry pi
- Not with that attitude!

Guessing this is a hotel bathroom by the looks of it.

Then it very likely has a mirror with integrated heating. I have one myself and love it.

It’s heated.

There's a ghost in your house that's trying to tell you "rectangle", but it's illiterate.

Try to figure out what "rectangle" means.

Nah, just means that the mirror can't render the Unicode character that the ghost has sent.
- It was the poop emoji

There are coatings /sprays for this

I think in this particular case it might be an integrated heating element like this: https://clearmirror.com/products/shower-clearmirror
They're popular in shower rooms in Japan.
You can also just rub some shaving cream on it and wipe it off.
- Or soap
/sprays
i read this as a tone marker

This comments section feels like schizophrenia.

These are such a good idea. It works by having a heater behind the mirror which prevents the condensation.
Wait until someone finds a screwdriver.

Don't believe any of the other comments, this is clearly a one-way mirror with a camera inside. That conspiracy theory you've been thinking about a lot lately is true, and even worse they know you are on to them. Remember that creak in the floorboards you dismissed as the house settling? Footsteps. The way your coffee mug was turned slightly counterclockwise this morning? Intentional. They watch you when you sleep, and know how much time you spend looking at your phone.

Or it's what the top comment said. Sleep tight!

Or it's what the top comment said. Sleep tight!
Writing this in the top comment doesn't help, like, at all...

I had this happen in a hotel, and being curious I removed the mirror, and yes there was a hole in the wall behind it, no there wasn't a camera there. It was just were they had ran the wiring for the lights on the mirror.

It would make sense that it serves like an access hatch to a terminal block that feeds the whole room. It's simple, costs nothing, is easy to get to (compared to having it sealed in the wall), protected from splashing and prying guests, and close to where you want most lights and outlets.

being curious I removed the mirror
protected from [...] prying guests,
- Nothing is protected from those willing to pry hard enough ;)

For anyone who wants to achieve the same effect take a dry bar of soap and rub some into an area of a mirror in whatever shape you like (circle, square etc). Then buff it out with a dry soft towel or cloth until you can no longer see the soap. Next time you take a shower that part of the mirror won't be fogged up. Reapply soap and buff out every couple weeks or so if you want it to stay that way.

I'm going to draw penises the next time at a friend's house
- I like to do this for my wife to find. She really loves that she's married to a 40yr old child.
- Hunted penises
I wanted to write "i see you" before I left my last apartment. Didn't get the nerve to do it because I worried someone would slip and fall

These are such a good idea. It works by having a mirror behind the heater which prevents the reflection.

Alright, but now the heater is in the way.
- Yeah, that's why it prevents the reflection

These are such a good idea. It works by having a heater behind the mirror which prevents the condensation.

Ps. Excuse the multiple posts. fedia.io was having a moment. I’ve deleted them now

Apparently no one here has been to a Home Depot or Lowe's in the last 15 years.
You can achieve a similar effect at home by using your hairdryer on the fogged-up mirror!
- You can achieve the same thing without wasting any (electric) energy by rubbing a bit of shaving cream onto the mirror and buffing it out. Works for a while.
- Well lah di dah ms "I own a hairdryer" /s

There is probably a hole cut into the wall there.

If you want an innocent explanation, then it's entirely possible that there used to be a medicine-cabinet-style mirror there. It looks like it's about that size and would fit in that location. Those medicine cabinets are recessed into the wall and so they require a hole to be cut in the wall. When they installed the large mirror, they didn't think it was worth it to repair the hole, since they were covering it up with a mirror.

If the hotel is fairly old, it might have had something like that in the past.

But since there is no way of knowing that for sure, if I was in that room, I'd assume there's a camera behind there, too.

Some hotels just put a hydrophilic coating on their mirrors. https://fsicti.com/markets/architectural-building/bathroom-mirror-shower-door/
- Even so, there is no reason to downvote my comment. It is possible for there to be a hole there. Voting like that just makes you an asshole. And, yes, comment votes are public information.

Maybe somebody's stashing delicious freshly baked goods back there?

Just posting to say I was here when everyone replied with "These are such a good idea. It works by having a heater behind the mirror which prevents the condensation."

Hahaha I just saw this. fedia.io was having a moment and posted my comment several times and everyone else has just run with it. Quality!

that’s the two-way section

Uninsulated heat leak behind.

These are such a good idea. It works by having a heater behind the mirror which prevents the condensation.

That's where you're going to tape up a spare towel. Plenty of area left to check your makeup.