A new candidate has been chosen. The magic examines their surroundings and tries to construct a suitable starting point.
Most of the structures around the candidate are made of rectangular prisms so their introductory room will be one of those. They tend to sleep on somewhat rounded rectangular prisms so it makes one of those too. Layers of fabric are arranged to build on that familiarity. Other furnishings are similarly loosely copied a desk, a couple chairs appropriately proportioned to the candidate's body.
Oh and the candidate and the others of their species seem to wear coverings most of the time. The precise details are too varied to extrapolate useful patterns so it just makes copies of all the coverings they've used in the last week and places them in a few bins to one side of the room. It does understand enough to clean and repair them so it does that.
With those basics handled it busies itself with tweaks to the other nearby parts of it's realm to provide for the candidates needs and then it waits for them to sleep.
Once they're deeply asleep it pulls them into itself and nestles them under the covers of the bed it prepared.