Iono, it's kinda neat, but it makes me kinda nervous and claustrophobic too. It's a borderline liminal space, it feels hollow and empty and samey even though there's a person in there.
Because if you have a problem while swimming you cannot easily get to the nearest edge and get out - the sheer wall prevents this. You are committed once you leave the end of the pool.
I think around here they're called communities, rather than sublemmies.
In the comparable subreddit, context was allowed in the comments, just not the title. Personally, I appreciated it many times. However, I understand forbidding it could enhance fascination.