I agree, I think the only appropriate time for an emoji is to acknowledge somebodies else's message but you don't have anything you want to say. A thumbs up or a celebrate.
I disagree, I think there's many times where a statement can clearly seem hostile, or jovial, at the same time, and adding some emojis to lean towards jovial will make it a 100% safe message.
Sure, you can add context in other ways, but it's quick, easy, and effective. Is it unprofessional? Perhaps in an email, but I don't consider every slack message something that should be "professional" in tone. You don't speak professionally to every person IRL (or, at least I hope you don't).
I have a small group of emoji that I turn to for this kind of color. :sweat_smile: for a note of self-aware awkwardness. :thinking: when I'm posing an idea without standing behind it too hard, or when my thoughts are continuing beyond the message I've just sent. A few others are not uncommon, but more situational.
(I'm using their Slack codes here, since I'm not sure I can just embed them directly in an HN comment...)
I tend to come across in text as very detail-oriented and precise, so some careful emoji usage helps recover some of the consideration that would normally be carried by tone or body language.
This type of use is exactly what I was talking about in my original post. It does wonders for positive communication. Even if some don't see the need for it, as the article discusses, you need to consider your full audience!
