The following kinds of activity are visible on the feed:
New Socials Created: All the new socials appear in the activity as soon as they are created.
Popular Socials: When you join a social, a new post appears on the activity. The more people join that social, the more times it appears on the feed and the more popular it becomes.
Social Reviews: The best reviews (4 and 5 stars) from past socials will be displayed on the activity stream.
Photos: When you upload a new photo to a social or chance your profile picture, the photos will appear on the feed.
Friend Connections: New friend connections will appear on the activity when a friend request is accepted and the connection is made. If you accept several requests at the same time you will get one single post with multiple people. If you accept requests over a longer period of time, individual posts will be created per new friend.