There's been lots of discussion about the unicorn over the years. Here's Ben commenting on another Devs post with his thoughts:

Ben Halpern

Sep 2 '18

Unicorns typically represent an especially positive connotation in our industry. Unicorn devs, unicorn companies, it’s the things that are wonderful.

Emoji reactions are always a bit abstract and I made no effort to dictate the purposes.

One thing to note: I’d like to have a longer list of reaction types you can choose from like in Slack, just haven’t gotten around to building that out, or even describing it to others.

A unicorn is something that is highly desirable but difficult to find or obtain.

When you apply that to DEV posts, I see it as reading a piece of information that I would find valuable to me.

So, the use of the unicorn icon is up to interpretation (probably on purpose). I think it’s a great symbol for expanding ideas and creativity.

// , It's another meaningless emoticon.

Why assign meaning to symbols when we can just float on in endless equivocation snurgle breep?