i would excuse it with "he is a vampire and shouldnt be seen in the mirror at all". so, you got a cursed reflection instead.

Are we all going to ignore the scene where he flat out looks in a mirror to check and see he was bitten?

Eh, either way it was mentioned below, modern mirrors use glass which do cast a reflection for vampires because older mirrors used silver. Which was a "holy metal" and thus wouldn't cast an unholy vampire.

The mirror is haunted.

"Screenspace reflection" is very common with games using EU4 or Unity. Cheaper than mirror level, better than cubemapping, less intensive than ray traycing. If you take care, you will start to notice this in a lot of games.

I thought his mirror image was weird enough

actualy its not mirrored and that the problem

is not a vampyre!!!

The answer is yes...

Vampires cant see their own reflection dudes

I think i remember reading something about Modern mirrors not doing this because the older ones had a silver backing which caused the lack of reflection.