This example builds a smiley face from modular React components rendered as SVG. A yellow background circle with a black stroke is combined with two eyes, positioned using offsets, and a mouth drawn with a D3 arc. The mouth’s shape is generated using the `d3.arc` API, specifying inner and outer radii and start/end angles. The React application uses ReactDOM to render the SVG structure, with all elements grouped and transformed to the canvas center.