As a courtesy to those of its occupants who prefer rooms, it does have a modality in which it presents itself that way: a room, with as many chairs as it needs, and a bulletin board, and a vending machine with candy and chips and concepts sold for nothing to anyone with the right prerequisites.
On the bulletin board, if one chooses to perceive it as a bulletin board (and not as a wiki or a flower or an ineffable cloud of information or an eternally malleable clay tablet) people whose only common trait is that they get to come here leave each other notes.
Notes about physics, about magic, about grand sweeps of narrative. Notes from people desperate to fix a never-ending heap of problems, smug about the condition of their homes, curious about the wider omniverse. Signed with names and sigils and "you ought to know who I am". Terse or verbose or nested with as much meaning as interests the reader.
In the vending machine, if one chooses to perceive it as a vending machine (and not a basket or a fruiting tree or a file repository or a crystalline fractal) are many things... and they have notes connecting them to their reviews on the bulletin board.
This one, for instance. She (it's usually, but not invariably, a she) has fairly glowing reviews from most of her previous purchasers. Here is what you need to install her; here are some things that are recommended for best results but optional especially if you just want to use her as a beacon for her other instances; here are some things she comes with as add-ons you can take or leave; here is what she is good for. The reviewers who don't like her are annoyed that theirs was too good at it, if you read between the lines. Well, that and the fact that if your universe is unpleasant enough sometimes these critters figure out how to flip you off and leave before they figure out how to solve all your problems. (There is a tangent thread about alternative solutions to similar problems which come bundled with stronger irrational attachment to their homes, but they have more stringent installation requirements.)
They come in these colors and styles; you will need to compensate for the following standard-issue drawbacks in some way if you require services of them that intersect with those areas of disability; they are only rated for upbringings of the following severity and are less likely to hate you if you stay thoroughly under that limit and less likely to fail at important goals if they are given opportunity to self-educate; if you have a way to generate them as instant adults they can begin work immediately but on the standard trajectory age six is the absolute earliest and teens is customary...
There is a chart (if one chooses to perceive it as a chart) of template interactions that have been tried before, but a lot of the more interesting accessory and companion templates are out-of-network for some visitors. What a pity.
"So it's sort of...like a lot of little portals, at the edge of your consciousness, and most of the time you don't pay any attention to them because none of them are for you know matter how loosely you interpret them, so they're like--glass windows--but every now and then, if you're pushing on them, it'll turn out that one could be interpreted to mean you, and the more generous in your interpretation you have to be to include yourself the harder the barrier is and the harder it is to push through it, so usually someone who fits better grabs it first, but sometimes you can manage to push through even one that feels like stiff rubber, and sometimes it's really definitely for you and then it's like there's no barrier at all."
"If the summons invokes you specifically then you might have to go depending on the summons involved, but if it wants 'a succubus' or 'a wrath demon' or allows leeway for the summonee to stay behind if they want then you can stay."
"Interesting for what? Unless you know enough summoning theory to draw interesting conclusions."
"I think if you're looking at its magical qualities you might want to study basic summoning theory before getting into obscure edge cases."
"Do you have to pretend to be different people every so often because you aren't getting older?"
"Hmmm." Pause. "Is there anything else I should know you can tell me about demons or Hell?"
"I might actually be out of questions for right now. But maybe if I think of something I could call you and if you think of something or want a snack you could call me?"
"...Sure, I think I have business cards here somewhere," she says, rummaging in her pockets.