The best thing being that while this Face Sculptor DOES dwell in Thieves Guild territory she is NOT Thieves Guild specific. This has made tweaking a character's face after many hours of gameplay with a really misguided bit of War Paint on their face an easy task, regardless of faction or role.
Troof.
I actually think this was a subtly brilliant addition to the game.
I assume it's non-canon, but the stuff the NPC says about walking with the Hollow Faced Men and some other faction of people got me really excited to learn more. More than likely it was just a reference to the Faceless Men of the Song of Ice and Fire saga but my ears perked up with interest.
That one face sculptor who says very little about things we have no lore information on was more interesting than 90% of the Skyrim NPCs.