This example renders a grid of procedurally generated smiley faces using React and D3 v7. Each face is composed of SVG shapes—a yellow background circle, black eyes, and a mouth created with the d3 `arc` generator. The `Face` component composes smaller components (`BackgroundCircle`, `Eyes`, `Mouth`) inside a `FaceContainer`, while the `App` maps over an array of 18 faces, randomizing eye offset, eye radius, mouth width, and mouth radius for each. The result is a playful, varied collection of faces displayed in a fixed-size SVG canvas.