Smiley Faces displays a grid of eighteen randomly generated cartoon faces, each with distinct eye size, eye offset, mouth thickness, and stroke width. The faces are rendered as SVG elements using React components for the face, skin, eyes, and mouth, with ReactDOM mounting the output. D3's `arc` generator creates the smile shape from a half-circle path, while `d3.range` produces the face count; all visual parameters are assigned via `Math.random()` at render time.