Unlike ‘like’ (the thumbs up icon), this function is for private use only. The page contains the pages your have added to Favorites sorted by groups. Favorites can contain any article or image from the following sections, Articles, Portfolios, Groups, Galleries. To add an article or an image to Favorites you need to click the star icon near the thumbs up icon on the target page.
Deleting material from the Favorites can be done in the same way, by clicking the star once again.