If the notorious monsters in limbus are mannequins (the spoiler image appears to be a mannequin in RDM gear), what do you think that could represent from a lore perspective?
The Delve NPC are mannequins.
The monstrosity NPC are also mannequins.
The High Tier Battlefield NPC are also mannequins.
In the mog house mannequin quest the mannequin is shown as being possessed by evil and brought back to life by a Necromancer from Tavnazia, a job they supposedly wanted to add to the game but felt was too dark (which they later changed into puppetmaster)
https://www.youtube.com/watch?v=w4rtQjc9Xu4