PS, I just noticed something! They claim:
"These variations are normal and are located primarily in the margin where text is not present"
Yet, the light variations are totally touching the lower lines of text where you read. So, what they did is have the menu up in the pictures, that way, indeed, you have a nice broad bottom margin and, indeed, the light cones do not touch the text of the book. Unbefrigginlieavable.