An SVG-based visualization demonstrates how masking layers create intersecting geometric patterns. The code renders 100 horizontal and vertical rectangles using D3's `select` and `range`, each masked by a circular region. Two SVG masks invert their black-and-white fills, producing a visible cross-shaped overlap at the center where the circles align. The grid lines only appear within the masked circular areas, creating a dynamic interplay of light and dark stripes against a blank canvas.