This example shows a partially constructed smiley face rendered as an SVG, with a yellow circular background, two black eyes, and the beginning of a mouth arc. The code builds the face using React components, where `BackgroundCircle` and `Eyes` are separate reusable functions, while the mouth is generated using D3’s `arc` generator with specified inner and outer radii and angular extents. The final SVG is rendered through ReactDOM, with explicit positioning via translation and coordinate offsets for the eyes.