This example displays a simple smiley face drawn with SVG shapes inside a React component. The face consists of a green circle with a black stroke for the head, two black circles for eyes, and a mouth created using an arc path. The code uses D3’s `arc` generator to define the mouth with specified inner and outer radii and angles, while React renders the SVG elements. The fixed viewport is 960 by 500 pixels, and the face is centered using a translation transform.