A smiling face drawn with SVG shapes animates its eyebrows up and down in a looping motion. The example uses D3.js v6 to construct the face from circles, rectangles, and an arc-generated mouth, centered within an SVG canvas. D3 transitions drive the eyebrow animation by repeatedly updating the transform attribute of the eyebrow group. The code imports `select` and `arc` from D3, with hardcoded dimensions for the facial features.