There’s almost always one guy who is “the omega worker,” like the lowest person on the totem pole that everyone uses like a bar one can’t cross. There has to be a “well, at least I am not THAT guy!” Opposite of the Alpha pack leader, this person is the other end. Yes, it’s abusive in toxic environments, but it’s nothing compared to the chaos that follows when that person leaves. The scramble to “not be at the bottom.”
No mention of external dimensions, so I am going to assume that it exists in the abstract since you mention teleportation. Like you just think about it and teleport there, not carry it upon your person like a portable hole in D&D.
Like others mentioned, a living space of some kind. I’d worry at first where I teleport inside, like hopefully not inside my mattress. Also, when I teleport back out, where is that? Where I teleported in? What if that gets replaced, like say I popped out while in an empty parking garage, but popped back in and a car is now parked where I left off? Might be nice if I pop back out anywhere I choose. Pop in while in New York, pop out in London.
Man, I’d save so much on rent. Or at least storage.