A grid of eighteen smiley faces, each with randomized facial features, fills the screen. The example demonstrates composing reusable React components for the face, eyes, mouth, and background circle, with D3's `arc` generator defining the mouth shape. Each face renders as an SVG element, and its properties—like stroke width, eye offset, and mouth radius—are generated using D3's `range` and `Math.random` to create variety across the grid.