This example creates an abstract geometric composition by layering two sets of 100 thin horizontal and vertical rectangles across the canvas. Two SVG masks, each containing a row of distinct D3 symbols (circle, cross, and other shapes), selectively reveal or hide the intersecting grid lines. The piece uses D3.js v7’s `select`, `range`, and `symbol` APIs to generate the shapes and masks, with the horizontal and vertical bars alternately shown or concealed depending on the mask’s fill logic.