In the playback screen, you have the option of adding a message (Note) to the session you're watching using the NOTE AND SHARE link at the bottom left of the screen. Type your observations from the session and click the NOTE button to add your comment as an event in the session timeline.
You can also use the link copy button to get a shareable link to send to interested parties. When the user clicks the link, they'll be taken to the moment you specified and see your note before diving in to the session.
If you want to share a link with someone outside of your FullStory account, you first have to enable Guest role.
Notes can also be shared via the Slack, Jira, or Trello integrations. These integrations can be configured to send the note automatically OR you can choose to selectively send. Once configured, you will be able to share notes directly to these collaboration tools by clicking on the Send to links from the events bar:
When you share a note, it will automatically be shared with all users in your account in the Notes view. You'll see all of you and your team's notes featured there in chronological order, with a button to watch the session instantly.