This example uses D3.js v5 to construct a yellow smiley face from SVG primitives, including circles for the eyes and an arc path for the mouth. The most notable behavior is an animated eyebrow movement, achieved by chaining `transition().duration(2000)` calls to shift the eyebrow group’s `transform` attribute up and back down. The code demonstrates fundamental DOM manipulation via `select` and `append`, and uses the `arc` generator to define the mouth’s path.