Featuring content is a right reserved for administrators for the space and system administrators.
To feature a content, you click on the action menu at the top of your Story and choose the "Feature" option. At any time, you can remove the featured content by following the same procedure and checking the "Unfeature" option.
When content is featured,it stays at the top of the Activity Feed of the space
If you highlight too much content, the library will seem to remain static. Use this option sparingly or remove the Library tab from your space by increasing smart tabs.