A smiley face composed of SVG shapes animates its eyebrows upward and downward in a looping motion. The face includes a yellow circle head, two black eyes, and a mouth drawn with an arc path. Built with D3.js v5, the code uses `select`, `append`, and `transition` APIs to select the SVG canvas, append geometric elements, and tween the eyebrow group’s transform attribute over two-second durations. The animation runs on page load, with dimensions and positions defined by fixed numeric constants.