A smiling face rendered in React and SVG shows two nearly identical overlapping faces built from a yellow circle, black-outlined face, eyes, and an arc-based smile. The code uses React components like `FaceContainer`, `BackgroundCircle`, `Eyes`, and `Mouth`, with D3’s `arc` generator to create the mouth path. Rendered via `ReactDOM.render` into a hidden-overflow body, the example demonstrates component reuse by displaying the same face twice with identical positional and sizing parameters.