The Craft team built an internal Figma plugin, "Flock" that helps organize and paginate frames into presentations. It's pretty sick, and to go along with it we created a branded icon that lives in the dropdown menu.
The OG concept sketch is in the bottom right.
Honorary mention of the "Cotton Ball" concept. I loved this little sheep, it played with the same core concept of a continuous line but didn't scale or connect as well as the "F" does.