Google's "Messages" client on Android has a feature where, in RCS chats, if you send or receive a message that solely consists of a single applicable emoji (and I believe in response to certain emoji reacts as well?), a little animation plays. The :joy: and related emojis trigger a "haha so funny"-type animation, :cry: and similar trigger a sad, rainy cloud, and so on.
An interesting thing I noticed recently is that :skull: triggers the same "haha so funny" animation as :joy: does! Which kind of surprised me, because I was using the skull to convey "lol I'm dead", so it fit here, but I wouldn't think that's the primary use for it.
Because "lol I'm dead = something is hilarious = :joy:". "Emoji evidence" is crazy. :skull: can mean a million other things, same with a (water) pistol emoji.
An interesting thing I noticed recently is that :skull: triggers the same "haha so funny" animation as :joy: does! Which kind of surprised me, because I was using the skull to convey "lol I'm dead", so it fit here, but I wouldn't think that's the primary use for it.