You're probably correct. I doubt that even Jobs and Ive are superhuman enough to build the right product at the beginning. I do wonder how they do this with their culture of secrecy. Any focus group they run must be quite small or they must be splitting up their focus group tests.

For example, I remember reading a story about someone testing out the iPhone UI alone in a contraption in a box as opposed to the real hardware.

I heard a while back that they would intentionally use fake products for testing to see what group leaked the information. Kind of like having a watermark in the review copies of the movies given to the academy and sundance.