This example demonstrates how to build an animated face using D3.js, starting with a yellow circle for the head and adding eyes, eyebrows, and a mouth via SVG shapes like circles, rectangles, and a path. The code uses `d3.select`, `d3.arc`, and chained `transition` calls to animate the eyebrows moving up and down over time. All elements are positioned relative to a centered group, and the face responds to the viewBox size defined in the HTML.