This example uses D3.js to construct a smiley face from SVG primitives, with animated eyebrows that move up and down. The code leverages `d3.select`, `d3.arc`, and chained transitions to manipulate the DOM directly, drawing a yellow circle, eyes, rectangular brows, and a mouth. The eyebrows animate via two sequential `transition().duration()` calls, shifting their vertical position over four seconds. All shapes are rendered in an SVG container with hardcoded dimensions and styling from an external stylesheet.