@AgentKuga
It's just my guess, but...
It's a dungeon.
The dungeon is a vast underground ruined library.
The robot maids are "Librarians" with the ability to identify the subject matter of the volumes/items they encounter. It's not clear if this is due to their containing a copy of the original shelving plan, or an understanding of the classification labels, or the ability to identify such items upon sight; an appraisal skill geared to library items, as it were.
They are prone to overload/failure. Hence the interchangeable upper torso units; that's where the AI resides. It's far cheaper to maintain a small number of ambulatory units and use interchangeable "knowledge" units when said units are prone to failure.
Items recovered from the ruined library are still subject to a two week checkout period, upon which they must be returned.
And, yes, this was rather odd.
I'll admit, being a former Librarian myself, the title was such that I had no choice but to examine this oneshot.