You remember the scene in A Christmas Story, after Ralphie has discovered the BB gun tucked behind the furniture, but before he has taken the rifle out into the snow, when the father is nervously muttering half-sentences as he at first tries to guide his son to load the gun, and he realizes with each half-finished sentence that Ralphie has been thinking about this all night, and that his son already knows full well how to load BBs in through a funnel and pump the stock?
This is like that but with Apple products. Yesterday's work with the iPad was weird, but that was a case of a kid manipulating a screen almost as big as her. It was a feat no more challenging than me pointing to Joe Buck's head on a 52" television. And the day before that she couldn't make heads or tails of the Sesame Street app.
Her work with the iPhone here -- lookit that left thumb cradling that thing like she's been playing Contra for years -- is a moment of freaky day-over-day brain development.