I think the talk about it being used to read a computer screen or a document on a desk is a red herring.
I think it's much more useful allowing you to confirm/discover somebody (BinLaden?) actually is somewhere
; or that a someplace
(communications center, weapons cache, control room?) is where the GPS coordinates say the phone is; or a something
('missing' tactical warhead, or guy in a 'bunny suit' holding a stoppered flask?) is in near proximity to the smartphone. All it would take is one quick glimpse.
Where there's a will there's a way. And where there's a confirmed coordinate
for a "high value" target, there's a guy in a van 500 miles away directing an MQ-1 Predator drone towards it.