>>7859572to me, its a space that has had it's context or purpose close to erased, but recognizable enough to be a human-made construct. abandoned malls, hotel alcoves with chairs that have never been sat in, school hallways after dark with no kids in them, and so on. despite being built by humans and existing in the real world, they almost look like a simulation of itself; a fake copy of a copy of a place that might exist.
to me, the "transitional space" definition of liminal isn't necessarily referencing the purpose of the space, but how it is a transitional space between what is real and what is unreal.