This example displays an abstract geometric pattern of thin horizontal and vertical lines across the full browser viewport. The lines are selectively revealed or hidden through two SVG masks, each populated with D3 symbols (such as circles and crosses) arranged in a row. Using D3’s selection join, the code creates 100 rectangles per axis and applies the masks via `svg.call`. The rendering is done entirely with SVG elements in React, leveraging d3’s `symbol` and `range` APIs.