A D3.js reproduction of a Sol LeWitt art piece uses SVG to render a grid of horizontal and vertical black bars over a full-screen canvas. Two circular masks, defined via SVG `<mask>` elements, create a central circular window: the first mask reveals a white circle, while the second inverts it with a black circle, producing a layered visual effect. The code uses `d3.select`, `d3.range`, and data joins (`append` and `join`) to generate 100 rect elements in each direction, with the masks controlling visibility.