Liminal spaces are the subject of an Internet aesthetic portraying empty or abandoned places that appear eerie, forlorn, and often surreal. Liminal spaces are commonly places of transition (pertaining to the concept of liminality) or of nostalgic appeal.
https://en.wikipedia.org/wiki/Liminal_space_(aesthetic)
People really misuse the word "liminal".
Sort of how "literally" became to be used as just emphasis.
A liminal space is occupying a position at, or on both sides of, a boundary or threshold. But because a lot of the liminal spaces had this vague creepy empty feeling, now people use "liminal" to mean "vaguely eery" or words to that effect.
An interpretation of that definition still works with context; these empty places feel like a metaphysical waiting room or purgatory, a space between this life and the next, between this dimension and the next, etc., depending on what spirituality, philosophy, or fantasy is convenient