Emoji reactions for topics, articles, events, etc.

To add a bit more colour to this, look at how tools like Dropbox Paper, and Slack have essentially trained their users to use emojis/reactions to communicate things like alignment, satisfaction, interest, acknowledgement, surprise, etc.

Also loved the additional idea you had to enable use of custom icons or emojis @Scott Baldwin, as this would help create a more unique community experience/culture based on your brand.

Just to add to this, it would also be helpful to have these options to react to a private message and with that, a notification for when something has been reacted to anywhere in the community.