I think it's worth noting that 2004-2006 was a time period where a Flash applet could have done this on the client. This was also a time when Flash content was supported by Apple QuickTime, so it's interesting that they didn't make use of it here.
I wonder if a SWF was ever hosted on the apple.com domain.
> This was also a time when Flash content was supported by Apple QuickTime
While QuickTime supported some Flash content, my recollection is that it only supported simple animations which could be mapped onto QuickTime's own interactive video features. I don't think it supported ActionScript, so this kind of interactivity would have been beyond it.
https://en.wikipedia.org/wiki/Thoughts_on_Flash
Apple had Adobe by the balls, and made the entire web a little sadder to protect their bottom line.