As a page author it's great to get feedback about the documentation you've added for your team. Not every piece of documentation warrants a full comment from each team member, so we gave you a way to show the author how the page made you feel without writing a comment or messaging them directly.
Everyone using Tettra with you has access to react to pages. To react after reading a page just click any one of the five reactions above the comment box.
We don't send out notifications in Slack for page reactions but the owner of that page will receive an update in their daily email digest about the reactions to their pages.