This interactive example shows a smiley face with animated eyebrows built using D3.js. The face is composed of SVG shapes—a yellow circle for the head, two circles for eyes, rectangles for eyebrows, and a path for the mouth—all centered via a transformed group. The eyebrows move up and down using chained `transition` calls with a 2000-millisecond duration. The code uses D3 v5 selectors to query the SVG, `arc` to generate the mouth’s path, and direct attribute setters for positioning.