Facebook appears to be testing new notification settings and formats. As you can see in the below screenshot, the typical notification is rather straightforward: "Jon Doe likes your photo" - where the name links to the profile page and action links to the receiving item (post, note, picture, etc). The below notification is quite different though: - it is an accepted friend request who apparently is "new to Facebook" - Facebook then shows the user profile image - and then encourages me to "welcome her" by suggesting friends (twice!) - and asks me to write on her wall
It certainly stands out visually. Additionally it is the first Facebook notification that is "actionable" rather than informational (with verbs like: 'suggest' and 'write').
