This example recreates a Sol LeWitt-inspired geometric composition using D3.js, displaying a grid of horizontal and vertical bars that intersect to form a pattern. The visualization uses two groups of rectangles, one arranged horizontally and one vertically, each masked to reveal a circular area in the center of the screen. SVG masks defined with `mask` and `circle` elements control the visibility, creating a layered effect where the bars appear only within the circular regions. The code leverages D3 selections and data joins with `select` and `range` to generate the rectangles dynamically.