I think i figured it out.
1000 pages of images with 40 rows and 200 columns of the repeating pattern of three dark squares with one light square vertically oriented. 1000x40x200 is 8,000,000.
I think those slivers are the cover of the Moby Dick it parodies, with each cover overlaid on the last, and the resolution absolutely destroyed to save storage space.
Long ago when reading slush for a NY publisher, I opened a package to find a 'manuscript' purporting to prove that the real value of pi was 22/7. 22/7 is a repeating decimal, which was typed out at length to cover one page. That page was then duplicated, at smaller sizes, until there was a page that was just covered in unreadable rectangular blocks. Then the page of unreadable blocks was copied for another 700 pages, and bound in stiff boards. The effect of flipping through it was much the same as described here, with the additional undertone of insanity.
I have a feeling the author compressed 8 million copies of Moby Dick with LZW compression using a huge token cache, then printed the binary results in a 1000-page book. Each successive copy would become smaller and smaller.