A smiling face is rendered as an SVG across modular React components, with a yellow background circle, two eyes, and an arc-based mouth. The code splits the face into separate ES6 modules for the background, eyes, and mouth, using React Fragments and the `arc()` generator from D3 v5 to define the mouth’s curved path. Everything is centered within an SVG canvas using a translated `<g>` group, with dimensions and offsets passed as props from the main app component.