A yellow circle with a black outline forms the face, flanked by two smaller circles for eyes and a curved arc for a mouth. The example demonstrates building a smiley face from basic SVG shapes using React and D3's `arc()` generator, which constructs the mouth path from start and end angles. The components are positioned via SVG transform, with specific offsets and radii for each element. The code relies on `ReactDOM.render` and D3 v7, rendering declaratively within an SVG container.