3 of 13Image
It looks like Google is introducing a moving mosaic of its Android heritage, showcasing its sugar-coated and alphabetically ordered OS timeline: Cup Cake (1.5), Donut (1.6), Eclair (2.0), Froyo (2.2), Gingerbread (2.3), Honeycomb (3.0), Ice Cream Sandwich (4.0), Jelly Bean (4.1) and KitKat/Key Lime Pie (4.4).
It's accessed by pressing and holding on the red KitKat logo.
At first glance 4.3.1 (left) and 4.4 (right) look the same, but icons for YouTube, Settings, Google Settings, Google and Voice search change. Google+ Photos also pops up in 4.4 while Messenger disappears. And there's the addition of QuickOffice of course.
It's all KitKat upfront, but at least in this preliminary build the OS is still officially called KeyLimePie. It's running on a Nexus 7 2013 edition.