As a follow up to the Tim Cook article in the New York Times, here is their one with Jonny Ive, Apple's primary designer, published around the same time.
Apple has always been a company that is about design as much as anything else. This is part of what makes it stand out from the other tech companies who are just that: tech companies concerned solely with the business of selling products. Its the design that attracts many people to there products in the first place, both the physical design and then, when using them, the user interface which has always been the best, most intuitive to use of all the companies.
Jonathan Ive is responsible for the design.