"PHILOSOPHICALLY SPEAKING...":

This interesting article by British philosophy lecturer Sally Latham uses emojis to explain emotivism, a concept that goes back to David Hume that argues moral judgments are based on the emotions triggered by a situation and not on the facts of the situation.  To an emotivist, applying words like "bad" means no more than one disapproves whereas words like "proper," "good," or "right" means one approves.

"The dictionary definition of an emoji is ‘a small digital image or icon used to express an idea or emotion in electronic communication’. They’re used to add emotional responses to expressions of fact; and yet I would argue that they convey no factual information themselves. Rather, just like moral judgments under the emotivist view, they express emotion and attempt to evoke it in others with the view to influencing action. Interestingly, it has been argued that Ludwig Wittgenstein introduced the concept of the emoji when he argued that pictorial representations can convey more information that language. In a 1938 lecture at Cambridge he claimed: “If I were a good draughtsman, I could convey an innumerable number of expressions by 4 strokes.” It is likely that Wittgenstein was thinking about more flexibility in pictorial representation than our current emojis allow, but that doesn’t affect the argument here.

"Let’s take an example of a text message:
You missed your philosophy class today.

"By adding an emoji we can express either approval or disapproval to this fact:
You missed your philosophy class today. 😁
You missed your philosophy class today. 🙁
You missed your philosophy class today. 😡

"Both the sad face emoji and the angry face emoji are equivalent to ‘you ought not to have’ in moral discourse. There is no factual dispute between the people who added the different emojis. If we say ‘murder is wrong’ or ‘murder is right’, then according to what I would like to call ‘emojivism’ this is no more than:
Murder 😁
Murder 🙁
Or perhaps:
Murder 😡

"My emoji is intended to arouse a similar feeling in you, but there is no truth or falsity to any use of them.  ... [I]f we agree on the facts and disagree about moral value then we must abandon attempts to convince each other otherwise. As [20th century British philosopher A.J.] Ayer wrote, 'It is because argument fails us when we come to deal with pure questions of value, as distinct from questions of fact, that we finally resort to mere abuse.' (This is strangely familiar when it comes to social media.) To illustrate using emojivism: we can debate the facts about eating meat – for example, do animals feel pain? Does eating meat provide health benefits? Is it bad for the environment? – but if we agree on all the facts and then end up with:
Eating meat 😁
Eating meat 🙁
then that’s the end of the matter.
"In summary, Ayer’s theory of ethical terms as symbols adding nothing to the content of the facts to which they are attached fits well with the idea of emojis as ethical terms. This leaves us with the somewhat troubling conclusion that ‘wrong’ is no more than 🙁. But I think Ayer would be 🙂 with that."
philosophynow.org/issues/135/Emojivism