I'm always interested in seeing how logographic writing systems solve issues with input, encoding, indexing, and the like.
When I text my Japanese friends, we tend to use a lot of emoji and (in-app) stickers. I think emoji have such a hold in Japan because 1. there's a big "cute" culture there, and 2. Japanese language is largely icon-based (logographic) already.
When I see emoji all over Reddit comments, Github READMEs, and code docs, I feel a frustrating culture mismatch. I'm glad HN strips them. But, there are situations where I use emoji and like them a lot.