Dual-Frequency Optical Illusion Grid

2x2 grid, 16:9, AI inferred topics: Anchor: A single image that reads unmistakably as [High-Frequency Subject] when viewed large and close, and unmistakably as [Low-Frequency Subject] when viewed as a thumbnail, squinted at, or seen from across a room ::4 Perceptual Mechanism: Spatial-frequency hybrid (Schyns–Oliva). The fine subject lives entirely in high-frequency detail — hair, edges, filigree, grain. The coarse subject lives entirely in low-frequency luminance blocking — broad light and dark masses. The two must share the same silhouette envelope so neither reading requires cropping ::4 Morphology: The coarse subject's dark masses are constructed FROM the fine subject's own features, never painted over them. No seams, no vignette, no compositing edge. Both readings occupy 100% of the frame ::3 Material Physics: [Medium]. Monochrome or near-monochrome so luminance carries all the low-frequency information ::3 Illumination: Single hard source positioned so that cast shadow does double duty as low-frequency mass ::2 Viewing Protocol: Test at 1600px and at 120px. Both readings must survive. If either fails at its own scale, the image fails ::2 Render Stack: hybrid image, spatial frequency stimulus, [Artist Style] ::1 Failure Condition: A cheap version shows both subjects at the same spatial frequency, so the eye sees a collage instead of a flip ::-1 Negative: [Negative Prompts] ::-1