A smiling face made of SVG shapes animates its eyebrows upward and downward in a loop. The yellow circular head, two eyes, and arc-shaped mouth are drawn with D3 selections and an `arc()` path generator. Eyebrow motion uses chained `transition().duration(2000)` calls to shift the group’s `transform` attribute. The example runs in React, rendering static SVG elements with D3 v5.