SBClockApplicationIconImageView
The Clock Icon in iOS 7 has live watch hands by default. Those are implemented in SBClockApplicationIconImageView (https://github.com/thomasfinch/iOS-7-SpringBoard-Headers/blob/master/SpringBoardHeaders/SBClockApplicationIconImageView.h).
SBClockApplicationIcon
SBClockApplicationIcon is merely a subclass of SBApplicationIcon returning SBClockApplicationIconImageView as the icon image view class. The Clock app (MobileTimer.app) has a special key called SBIconClass in its Info.plist, the value is SBClockAppicationIcon. This sets the clock icon class to the live icon.