Can I get one for Astarion?

As I recall, the "Vampires have no reflection" stemmed from mirrors of the time usually being polished silver. So, I guess the vampire can do this if they're okay with having silver pressed up against their face.

Tbf the silver is behind the layer of glass
- Pretty sure they just poured silver nitrate over glass. You can still buy kits to do that to re-silver old mirrors for the original look. From what I can find, the layered ones were older, and they used tin and mercury which made breaking a mirror a rather unlucky event.
I always heard it was about not having a soul.
- Can confirm. I'm not a vampire but I sold my soul for a bag of Cool Ranch Doritos back im 6th grade. Since then I haven't seen my reflection or been able to use an automatic door.
- Good myths have multiple ramifications
Mirrors now are chemically deposited silver to my knowledge.
Deposited on the back of the glass, then a protective layer applied on top. The amount of silver in that assembly is very low, and none is exposed, but the reflective component is the silver.
- Most use aluminium nowadays afaik.
You can easily solve this with a little padding around the edges.

Would this work? I think the light stops at the mirror because it's silver.

Normally

Light hits the vampire.
It bounces off their body.
It hits the mirror
It reflects from the mirror into your eyes.

Silver mirror

Light hits the vampire.
It bounces off their body (now unholy light)
It hits the mirror and gets absorbed
Light doesn't make it to your eyes

So, technically, there really should be a vampire-shaped hole in the mirror where the vampire was.

The idea that light has a binary property of holy versus unholy is pretty funny. You could probably exploit this to do computing.
- COMPUTERS ARE VAMPIRES?!
- inb4 arbitrary code execution poc on github
Will you DM a game for me?
- You have added The Unholy Spectroscope to your inventory.
  The concept of unholy light seems to imply vampires can be detected through unholy spectroscopy.
If I’m standing next to a vampire and give them the shirt off my back, does my shirt turn invisible in the mirror when they put it on?
If a vampire gives me their shirt, at what point does it become visible in the mirror?
What if the vampire is wearing a rope- can they spool out a hundred feet of mirror-invisible rope as long as some is on their body?
I feel there’s a ton of applications for vampires- optics use mirrors a lot, can they wear a vehicle/tank/ship/etc and make it invisible to optics that utilize mirrors?
- Well, if we treat incoming light as a quantum superposition:
  |light⟩ = α|holy⟩ + β|unholy⟩
  ...and assume that vampires reflect only unholy light and absorb holy light, then anything directly part of the vampire’s "system" filters light this way.
  So I guess the question becomes, "How does the filtering happen?" Is it by physical surface, or is there some kind of quantum holiness field that absorbs holy light nearby?
I always thought it was a quantum effect: light is passing through the vampire and bouncing on it at the same time and it's only when you observe its predicted path that you'll project it in a defined state.
But, from your point of view, light "knew" from the beginning that it had to pass through the vampire or bounce on it.
- I don't think the light "knew" from the beginning. The light started in a state of superposition, right? Both unholy and holy. Once it hits the vampire, only the unholy light is reflected, acting like a sort of filter similar to a polarizing lens.

The better solution

Bicycle vamps

This belongs in What We Do In The Shadows.

I thought all of their clothes disappear in mirrors, too. Or what about water that they're drinking...

Vampires drink blood, not water...
- Surely, they must take in fluids besides blood, right? Otherwise they'd shrivel up!

I'll keep this in mind if I ever become a vampire.

Vampires also have ultra instance senses, so they don't need to look.behind them

Something a vampire-hunter might say 🤔

A hall of mirrors would be hell for a vampire to navigate.

Nah. It'd be like it is on a poorly made video game.

Can someone please put a vampire in a Michelson interferometer and see what happens?

Pretty sure your eyes can't focus on anything that close. Nice try

Try it out. Take a mirror, put it very close to your eye but angled sideways, since you can obviously not look through your head.
You will have no issues at all focussing on what you are looking at, since you aren't looking at the mirror at all.
You can also try that while looking at yourself through a dirty mirror. You can either focus on the dirt on the mirror or on your face. You can't see both the dirt and your face in focus at the same time.
I had a pair of glasses that had mirrors on the far sides of them and they worked rather well.

Oh that handsome little devil.