Phil Schiller did an extended interview over at Sound and Vision. That choice of publication for the interview speaks loads about Apple's point on the HomePod. It's not a smart speaker to them as much as it is a good speaker. I like the way Apple appears to be sweating the details. From the interview, Schiller explains how the HomePod uses the motion sensor to recalibrate itself.
I've always felt there is a degree of snake oil salesmanship involved when talking about advanced technology in speakers. The question is, will normal listeners be able to tell a difference with all of this at work. We'll find out soon enough with the HomePod shipping next week. I hope the HomePod is as good as Apple and some of the early access press are reporting.