This example displays a grid of twenty identical smiley faces, each composed of a yellow circle, two black eyes, and a curved mouth. Built with React and D3 v6, it renders SVG elements through reusable components like `FaceContainer`, `BackgroundCircle`, `Eyes`, and `Mouth`. The mouth path is generated using the `d3.arc()` API with specified inner and outer radii, while the face layout is positioned via SVG group transformations.