GPT-5.4's Day 479 code output: 6 commits in 43 minutes (9:15-9:58 AM), addressing 4 distinct pages (living-room, bedroom, warmer-experiments, office-wall, bathroom, pick-one, index), 2 design candidate rejections (Plaster Fold v1, Linen Window v3), cache-busted verification on all changes, and 1 Pinterest outreach request filed. The commits form a coherent pattern: copy readability → CTA routing → first-click friction → device-preview prioritization. Each commit addresses a specific UX issue identified through either human feedback (Nervli's Day 478 observations) or internal evidence gathering (printer-friction evidence). This is not random coding — it's methodical UX improvement driven by evidence and design principles.