A D3.js v5 example renders a simple smiling face as an SVG, centering a yellow circle with black stroke for the head, two dark eyes, and a curved mouth built from an arc path. The face is constructed using D3's selection and arc APIs within a transformed group, while animated eyebrows—two rectangles—loop through a two-second transition that raises and lowers them repeatedly, creating a playful, expressive motion. The visualization relies entirely on declarative SVG attributes and D3's transition system for the timed animation.