30 days of writing, day 12 (worldbuilding)

12. In what story did you feel you did the best job of world building? Any side-notes on it you’d like to share?
Since I write mostly VERY short stories, this is a bit hard to answer.
"On Sharing One's Feelings" is mostly about shining a light on a worldbuilding aspect, "Identity" hints at something I have come across less frequently...

I dunno, you tell me. :P