Two alternating line grids are masked into interlocking black-and-white bands and geometric symbols, reproducing a Sol LeWitt wall drawing. The SVG uses d3.mask elements, d3.range, d3.symbol and d3.symbols to generate vertical and horizontal line rectangles and rotating symbol shapes. Mask colors flip according to grid position and inner/outer layer, creating mirrored contrast. The code updates mask geometry dynamically with d3 joins, and renders to the full viewport using plain SVG attributes.