This piece by Brittany Darwell in Inside Facebook about the new Poke application actually serves to describe Facebook's constant aesthetic over the years.
Too close for missiles, Facebook switches to guns and has some fun with Poke
Dec 23rd, 2012
Facebook’s new Poke app seems in many ways like a departure for the company.
While most of Facebook’s products are meant to preserve memories and save interactions, communications in Poke disappear after a few seconds. Facebook emphasizes functionality over flair and tends to put a lot of structure to how and what users share, but Poke lets users doodle over their
photos with different colors and send virtual pokes to their friends. Most of all, Poke is playful while the rest of Facebook is very much a utility. If you haven’t tried Poke, you can get a quick sense of this by listening to the app’s silly notification sound — reportedly recorded by Mark Zuckerberg himself.
Although some aspects of Poke might seem out of character for the Facebook most of us know now, it’s actually a fitting addition to the platform with roots in Facebook’s past.
Continues at link