The danger of relying overmuch on emojis
What the user may mean by inserting a standard smiley, especially into a very short post or comment, won't necessarily enable every reader to interpret it in that particular sense, because the emoji covers such a wide range of possible meanings, eg from "I like this" to "How ridiculous" and everything in between.
So do let's all try to communicate what we mean accurately and not rely overmuch on these dangerously ambiguous short-cuts.