We've delved into just what we think of Windows Phone 8's interface, but not what led Microsoft to the final layout. The company isn't content to let us wonder -- a pair of new company blog posts explain some (though not all) of what was involved in that birthing process. Ignore the marketing spin and you'll learn that the wider, more densely packed home screen was chosen as much for balance as to stuff in more home tiles, and that it caused a momentary crisis for the app list as a result. The Redmond team goes on to justify choices behind the lock screen, such as why notifications are as customizable as they are, why the music controls fade and why there's a failsafe for PIN attempts. Don't expect to come out of the explanations suddenly craving a Lumia 920; just expect to make more sense of the OS inside.