Conversely, it can't be discounted that the fashion might follow functionality. Apples has a lot more experience than Google at creating comprehensively great user experiences.

Google's signature successes, Search and Mail, have wildly different success criteria for user satisfaction than an operating system. Apple's signature successes all have operating systems and then there is the iPod which is a bit different.

The iPhone is differentiated by much more than Apple's marketing. Everybody markets their product.