One final tidbit about iOS 7.1 (for now): the incoming call screen now shows a small portrait in the upper-right; previously, it was a full screen portrait. Why the change? Well, if you’ve looked at many of the screenshot galleries, you’ve probably noticed that most of them don’t show any portrait at all, because the phone owner hasn’t added photos to their contacts.
Even if you’ve ensured that all of your contacts do have photos, those photos probably don’t have the beautiful focus and smooth depth of field of a stock photo. It’s the same problem that Facebook Home faced: you probably don’t have a lot of professional photographer friends, so most of your friends’ photos probably have lousy lighting and poor focus wrapped in a low-quality image.
This is probably the impetus for the change to the lock screen layout. I have no special insider knowledge or anything, but it seems like the most pragmatic reason.