"Language as she is spoke" is very often at odds with literal dictionary definitions. So you're right that a liminal space is a transitional space, and that a metro is by definition that. But linimal aesthetic is different, especially as has recently become popular. It means a space that gives you that feeling of being between, of emptiness, introspection. A metro station absolutely does not have this aesthetic, except maybe at some mysterious hour where there's no one using it (and I've used them at both closing and opening times, they're never empty).
> But linimal aesthetic is different, especially as has recently become popular.
Your articulation of a liminal aesthetic hits upon the tension inherit in the word “liminal”.
By definition “liminal” signals “in between” which connotes an unsettledness or indeterminacy, or what in other realms is called the uncanny. This liminal aesthetic, at its core, is shot through with a sense of the uncanny, and empty devoid spaces where normally there is a lot of traffic convey this aesthetic clearly and succinctly.
Thank you for drawing this distinction.
My intent when referring to the denotation of “liminal” was to remind that even familiar places, such as bustling train stations and busy airport terminals, are also liminal spaces even if they don’t conform to current representations of the liminal _aesthetic_. By preserving the denotation of the word “liminal”, we can defamiliarize such spaces and recover (or emphasize) their liminality.
All of which is the message of art like Brian Eno’s “Music for Airports”. Who doesn’t appreciate the defamiliarization of our “mundane” traversals of the realms we inhabit?
Good luck preserving the meaning of words. Words have no meaning outside how people use them to express ideas. Words can and do change to mean different things, or even 'literally' the opposite of themselves.