I believe that it stems from, in my case, being tired and a phenomena us men experience called laziness! As Paul says in the PhotoReading Activator tape: "the photoreading system is as easy as looking at which hand your watch is on."
...not the most profound metaphor I've heard!! 
Though, I imagine he's creating an NLP anchor where, as one feels tired and anxious due to the process taking up much time, one looks at ones watch. In so doing, instead of reinforcing time-anxiety, one reinforces the idea that photoreading is a delight to do.
