The difference in screen size from the iPhone 3GS, the standard
iPhone available at the time, to the original iPad is a factor of
2.7 times — which turns out to be the exact same factor between
the iPhone 6/6s and the iPad Pro.
Update: I don’t think 2.7 is a magic scaling factor, I just think it’s funny how the numbers work out like this sometimes. The main thing is that the screen width of the Pro is about the same as the screen height of the “regular” size iPad Air. (And the Mini’s screen height is about the same as the width of the Air.)
★ Monday, 14 September 2015