A D3.js reproduction of a Sol LeWitt wall drawing combines horizontal and vertical bars into a grid. The SVG uses two masked groups: one layer of horizontal rectangles and another of vertical rectangles, each clipped by a circular mask created with `d3.select` and `attr`. The masks invert their fills, revealing a centered circle where the bars intersect. The code uses `d3.range` and data joins to generate 100 rects per axis, resizing to the full browser window.