India, Sept. 10 -- Apple's September 9 event-Surprise and Shine-began with a signature but unmistakable act of succession. Tim Cook's voice was heard first in the opening film as the camera tracked a mysterious figure before saying, "That's your guy. That's your opener." The figure was John Ternus. With that, a new leadership legacy unfolds at Apple.

This was Ternus's first Apple event as CEO, just days after he succeeded Cook. There was a certain aptness to the product at the heart of his first major launch - Apple's first foldable iPhone, a device that asks whether the company's familiar formula-wait, refine and arrive with something more complete-still works in a market Samsung has spent years building.

Conspicuously absent from the ...