For some reason I always liked this room. Although the cutscene with the villager always scared me as a kid.
I'm taking time frame into account when choosing paintings (unless I made them myself of course).
I thought the Vanitas (Jacob de Gheyn, 1603) was a good fit opposite the mirror. For the larger painting I wanted something with a lot of detail to take advantage of the higher resolution. The Triumph of Death (Pieter Bruegel the Elder, 1562) seemed appropriate. I'm also considering placing the rip of the original texture into the painting but currently I'm planning on having another ripped painting elsewhere in the level.
In some place I really want to include a painting of Shanoa from Order of Ecclessia to somewhat tighten the timeline. If I finish it it will likely look somewhat like this, although for reasons of copyright I'd probably make the picture myself instead of using official art.