Ales,
What you call wall eyed view is generally called parallel vision. Yes, that is the focus you want for photoreading. Don't worry if it wasn't very successful planting a stereo picture into the book while doing it... if you practice looking at 3D stereo pictures as an aside from photoreading you'll know how it feels when you are looking at them and can apply that focus to photoreading.
The image in the photoreading manual is kind of tricky because unlike most 3D images where the main image is in the middle of the page... the image itself is around the edges making the center look empty 
in fact if you look at this one because the image is near the boarder it looks like looking into a cave.
To help visually I'll give you a couple of links that may help
http://www.vision3d.com/stereo.html
This link will explain 3D vsion
http://www.vision3d.com/3views.html
This one shows parallel vison (photofocus ) As well as cross eyes (not photofocus)
Scroll down to the bottom of the page and check out the links showing methods of achieving photofocus...
Alex
