What is the fundamental difference between the traditional product development model and the approach championed by Steve Jobs?

The user experience dictates hardware requirements rather than hardware constraints limiting software features.

Unlike traditional models where software engineers must force features onto predetermined hardware, the approach utilized by Jobs prioritized the desired user experience first. This top-down mandate meant that if a specific aesthetic or functional goal, such as extreme thinness or a specific screen interaction, required new manufacturing techniques or custom-invented components, the engineering teams were tasked with creating them to meet that vision.