Fable
The brocade institute handed the snow-removal diagram to the master who reads cloth by grid
The brocade workshop first repaired the snow-stained canvas by having the old mender follow the cracks and color boundaries, patching bit by bit. When the canvas was small, he knew where to look first.
Later the royal palace wanted a giant tapestry, and the image was divided into hundreds or thousands of pieces. The old method of working along the edges was very stable, but it struggled to understand the relationship between distant lights and nearby figures at the same time.
The director first had more restorers work in separate zones. Each zone was clean on its own, but when assembled, the sky's light, the figures' orientations and the distant flags contradicted one another.
The young master cut the brocade into many small squares. Each square first announced how much snow it carried and what colors were nearby, then all the squares exchanged messages round after round.
At first everyone worried that the grid was too fragmented to see the whole. But after swapping, the distant red flag would affect the reflection on nearby armor, and the brightness of the sky would also constrain the shadows on the ground.
Repair no longer relied only on local patterns; instead, the whole painting renegotiated at every snow-removal step. The weaving institute later found that this method was best suited to large paintings: it could process in blocks while letting distant and near clues hear each other.
The young master also stipulated that every round of snow removal must preserve the relationships of the whole painting. You cannot ignore the light source in the upper right just because the lower left looks like a tree; you cannot let a character's shadow break just because the local color looks pleasing.
The larger the giant tapestry, the more important this mutual messaging becomes. Small cells handle the details, while global communication keeps the details from conflicting. Only then did the director understand that partitioning is not fragmentation, but a way to let a large painting restore order step by step. Later, when newcomers started, the master craftsmen no longer began with abstract terms, but had them review that failure: where intuition had been relied on before, why the first repair was insufficient, and how the new arrangement kept risk in a place that could be checked. Only when they could explain these details clearly and also point out when to follow the old approach and when to upgrade were they considered to truly understand this method. Later they also had newcomers practice this method: first have newcomers do it the old way and see how errors arise; then redo it under the new rules and see which step was blocked earlier and which step left evidence. If newcomers could only recite names, they would still misuse it in similar scenarios; only those who could state the applicable boundaries, the costs and the remedies after failure were allowed to take on work independently.