I was 
about emoji, and how they support human communication, especially digitally.
Consider an emoji “reaction” to a piece of discussion. One way to classify the user interface is based on availability.
Zero emoji available might indicate a technical challenge to implement, or it may be intentional so reactions are not considered part of the discussion.
A single emoji available gives users a binary choice: default or react. An example is when there is a 
or 
reaction, just the single type of emoji for that particular signal.
Next, we have a limited amount available, as opposed to unlimited options. Creating such a group of options may address accessibility and interface concerns. It may also address a “blessed” set of reactions the platform or operators wish to enforce.
And then there is an unlimited/all options available. This allows for any reaction symbol in the set to be applied to the piece of discussion.