Look at the wall behind the left shoulder of the girl in the middle. The entire contraption, I think, is for, shall we say, personal business. The big bowl for washing one’s hands, and the big circular gizmo above it I think is the predecesser to the modern toilet seat. Allows the user to sit [more or less] comfortably while above the chamber pot.
Is the entire device all one contraption? Like is the user’s head beneath the washbowl while she sits and poops? And it seems to be in an attic - did they keep these things handy in every room in the Edwardian Era (before bathrooms)?
It looks like there’s a smaller version behind the other girl and a high chair behind the third girl. I might be off a few decades, but I thought they had a “water closet” for ablutions and “the loo” was another term for it, derived from “visiting Lady Louisa.”