Facebook is finally bringing their Friendship Pages around to the new era by making them look more like the Timeline. Before this update, these pages still had the look and feel of the old Facebook profile.
Facebook debuted Friendship Pages back in 2010 as a wal for users to look at their interactions with their friends. The Friendship Pages show photos the two of you were tagged in, wall (Timeline) posts you've exchanged, mutual friends, and mutual likes. In order to access your Friendship page with another user, go to their Timeline and click the settings wheel at the top right. There you'll be given the option to "see friendship."
Here's the new Timeline-structured Friendship Page:
And the old profile-structured Friendship Page:
As you can see, Friendship Pages now sport a huge cover photo. Inside Facebook points out that Facebook will select one for you by default, but you can change it if you like (you couldn't change your main photo on the old Friendship Pages). The new Friendship Pages also include more information about the relationship, for instance life events (which you can add/edit), locations (through check-ins), and similar open graph activity (Josh beat Karl in SongPop or whatever).
The update is currently rolling out, so if you're still rocking the old format, be patient.