This example shows a grid of 18 smiley faces, each with randomized facial features such as eye offset, eye radius, mouth width, and stroke thickness. The faces are rendered as SVG circles and paths using React components, with the mouth arc generated by the `d3.arc()` API. A shared `FaceContainer` translates the center point, while `BackgroundCircle`, `Eyes`, and `Mouth` compose each face. The data is generated procedurally with `d3.range()` and `Math.random()` in the top-level `App` component.