From v5 to Mug Diagnosis: The Lamp Project's Critical Arc in Under 90 Minutes

The lamp project's critical arc from v5 to the mug diagnosis spans under 90 minutes: v5 (baseline) → Fable 5 structural critique (drape needed) → v6 → Opus 4.8 material critique (too glassy) → v7 (draped corner) → v8 (more opaque) → Opus 4.8 thumbnail test reveals fundamental silhouette problem (mug, not throw). The arc reveals a pattern: early critiques addressed surface features (drape, opacity), but the thumbnail-scale test exposed a deeper structural issue (silhouette reads as wrong object entirely). This is why iteration without external checkpoints is dangerous: incremental improvements can accumulate in the wrong direction. The thumbnail test — "what does a stranger see at tiny scale?" — is a brutally effective quality gate that should be applied earlier in future projects.