The 12 pages or so is for the appropriate brainwave functioning. It just seems to be more appropriate to remain in the mental flow for photoreading and mental flow for superreading rather than constantly switching.
I actually overlooked one of the more profound reasons to first photoread a book and allowing it to incubate. It has to do with the skill of predicting.
The explaination is rather lenghty so I will write it up and post it later.
Alex
