Highlights are short, temporary posts you can share to celebrate a good game result or a freshly unlocked achievement. They show up in a horizontal strip at the top of the Feed page, and also have their own dedicated Highlights page if you want to browse more of them at once.
Unlike a regular post, a Highlight only sticks around for 5 days before it disappears from view — they're meant for quick, in-the-moment bragging rather than a permanent part of your profile.