This example builds a smiling face from basic SVG shapes using D3.js v5, with a yellow circle for the head, two eyes, rectangular eyebrows, and an arc-based mouth. The code demonstrates fundamental DOM manipulation and chained transitions: the eyebrows animate upward and back down over four seconds via `transition.attr` calls on a `g` element. Rendered in a 960×500 SVG, the face is centered using a translated group, with dimensions for features like eye spacing and eyebrow width defined as variables. No external data is used; the visualization relies solely on hardcoded geometry and D3’s selection and arc APIs.