It's hard to get more specific than that, because it's happening very abruptly and extremely much.
It doesn't hurt exactly, but it definitely feels like something, a whole lot of it, whatever it is, and it goes on kind of uncomfortably long, and then—
First, she feels the new things. She (is? has?) this space: five cells by five, with a three-cell-wide installation in the center.
The installation is in much better shape than it was when last she saw it, and also looks very different: the arms are gone, and where the central well once sat, a geodesic dome of iron and glass surrounds a mysterious radiance which casts beams of light out through a random selection of its facets to illuminate the white plaster which now covers the ceiling and walls. It's not quite tall enough to brush the ceiling, nor quite wide enough to completely fill its three-cell square; but it stands on a raised circular platform ringed by concentric steps, and the edges of the lowest step stop just shy of that invisible-but-perceptible border. Platform, steps, and floor are all made of dark wood.
Also, her body is lying on the floor at the base of the steps, perfectly healthy, still wearing and carrying all the same things as when she last saw it, and it has its eyes closed. It's still just as much hers as it was before, but it is now a much smaller proportion of her direct sensory input.
(Well, all the same things with one exception—her book, instead of being in her pocket, is lying on the floor next to her hand.)
Her sense of the tunnels is much dimmer; they don't (yet?) belong to her in the way that this room does. She can see into them from her current large square vantage, but she'd have to go look at them herself if she wanted to see them directly. Or she could send a—
There isn't a word for the thing, but this is a potential she has: to create a slightly-autonomous creature at her dome, which can be directed to perform tasks. Sort of a cross between a magical servant and an extension of herself.
She doesn't have any other such potentials looming large in her thoughts, but there's a sense that she'd have more options were she not so constrained on space.