Author economical visual tests — full visual coverage in the fewest billable snapshots. Applies to any per-snapshot visual tool (UI Verify, Chromatic, Percy, Playwright screenshots), which all bill and diff per rendered story/test. Use when a component's variants/states are exploding into one snapshot per combination, when the visual-testing bill or noise is driven by snapshot count, or when writing new stories/captures and you want the cheapest layout that still covers every variant. Covers gallery/matrix stories, data-driven states, and the coarse-granularity tradeoff.