@ArmedCarp Their everything is dirty. The wallpaper is extra special like that to a degree that bothers me on some level (though it's a neat look).
The mirror thing isn't too unrealistic, though -- they're actually pretty dead on with that quirk. They didn't have the kinds of materials we do to make or seal them against degrading; they wouldn't get even remotely close for another 100 years or so. Typically, they would essentially rust out or tarnish, especially in hot, humid climates, and would need to be recoated/restored/etc. with some frequency.
(Font of useless knowledge, I know; every art project fills my head with some other bit of trivia I will really never, ever need again.)