it's most similar to upvoting, but with more emoji. So imagine if HN had an upvote on IOS, but instead on android it left a full message saying

>__MatrixMan__ reacted to this comment with "Upvote"

Much clunkier. his was fixed with RCS, fortunately, but that was the norm for some decade or so when talking with iPhones.

Oh, do iPhone users also see those messages when an android user is in the chat?

I had assumed that reactions worked fine for them and they were unaware that their iPhone was making them look like a bit of a buffoon to the rest of us.