Use abstraction, not metaphor, for software user interface design

So proclaimed Nick Disabato in Cadence & Slang (2nd edition) and he linked to https://www.wired.com/2013/06/the-future-of-design-is-more-than-making-apple-ios-flat/

… still not getting a heck of a lot of practical advice out of either source. I sort of get the concept…