Have you used the technique on another book?
Photoreading is for reading and learning. Reading to gain understanding. If you want memory tricks Try Tony Buzans book Use your Memory. Photoreading isn't a shortcut to a Photographic (eidetic) memory. The experiences mentioned in the book are the result of using the technique and applying manual activation on many books. Photoread and activate more books is the way to go toward achieving that. And yes, I have had experiences along the lines mentioned in the book and most of the books that I photoread I still manually activate.
Why anyone would want to memorise a book I don't understand. To me it is more a point of understanding what I read and making use of that information a parrot has an eidetic memory but I wouldn't ask it for advise would you? 
Alex
