I've personally only ever seen these bubble domes in real life in aquarium settings, which I 200% don't think is related to. The terrestrial species I most associate them with, prairie dogs, are already in game, so I'm struggling to think of what they might be intended to go with - new habitat building features like this typically have a specific new animal they're intended to play off of. The bubble in the picture also seems incredibly large compared to the size they seem to be in real zoos. Maybe that's just to accommodate entire groups using them at once, but if this is the only size option, that does seem like it would be a bit clunky. Maybe it's just a perspective thing, though. Or maybe it's not actually a bubble at all, who knows.
I'm also not sure I'm ready to jump to this being a children's or petting zoo pack, even though I think I'm generally more open to that idea than most of this forum. I'm ultimately still on the side that would prefer the children's zoo concept we've mostly honed in on here (goat, waterfowl, monkey, mara or something similar) over a straight petting zoo domestics pack, but I think the latter is probably the likelier pack... even though, again, I'm still not convinced this changes what we should expect on the whole.
Either way, just over three hours till we should have a bit of a better idea!