updated 03:35 pm EDT, Mon June 3, 2013
May reflect 'flat' design brought in by Jonathan Ive
A photo tweeted by 9to5Mac may show the homescreen in an alpha version of iOS 7. Layout mostly resembles iOS 6; one difference, though, is that icons have a "flat" appearance. iOS 7 has changed dramatically since the photo was taken, the source of the image says.
The firmware is due to be shown at Apple's WWDC in San Francisco, which starts June 10th. A flat look would be consistent with rumors that lead designer Jonathan Ive is abandoning the skeuomorphism favored by former iOS head Scott Forstall. Many other differences have also been hinted at, such as Flickr and Vimeo integration, and overhauled Mail and Calendar apps.