Clean, chrome-and-glass bookshelves and a glittering array of climate- and chrono-controlled display cases fill the marble-floored room; the immaculate glassy glitter of them distorts most sentients' spatial sense, such that it's very difficult to see how far the room extends. The cases hold a wide variety of objects, some of which seem to fade in and out of being (or at least, in and out of this reality).
The Archivist can often be seen wandering the room taking inventory on a neat datapad, or cleaning one of the exhibits, or curled up at a low table thumbing through one of the books. Though zie is courteous to visitors -- the Collection is kept open to the public, thanks to strong inhibitors preventing even the most determined thief or vandal from removing or damaging the items -- it is clear that, as far as zie is concerned, the Collection is for the benefit of scholars, not for entertainment purposes.
Nonetheless, many of the exhibits are enormously entertaining.
The Department for Parachonotic Research and Retrieval maintains the Collection to house the important items it retrieves from alternate timelines for study and use by Up's scholars and leaders. The items are culled from Puzzleboxes-that-weren't, from Messes-that-might-have-been. Their originating timelines range from extraordinarily similar to the 'home' timeline (which is formally designated "Puzzlebox One" by DST agents) to wildly different.