There is no such hand in touchscreen computer devices. The
touchscreen has no texture variation, has no physical surface
information, is dead flat, reflects ambient light noise, and
features oily fingerprint debris when seen at a raking angle. Also
the elegant sharp edges that encase many touchscreens require
users to desensitize their hands in order to ignore the physical
discomfort produced by the aggressive edges. Last year in
Cupertino, I yelled at some people about touchscreens that paid
precise attention to finger touches from the user but not to how
the device in turn touches the hands of the user (and produces
divot edge-lines in the flesh).
Beautiful little essay, but it’s pretty clear Tufte is not a fan of the iPhone 4(S) hardware.