A smiley face rendered with React and D3 displays a yellow circle with black-outlined features, including eyes, eyebrows, and a mouth, all centered on a 960 by 500 SVG canvas. The code uses D3’s `arc()` generator to create the curved mouth, lips, and eyebrows, while React manages the component structure and DOM updates. Static positioning values for offsets and radii define the facial geometry, and the SVG is drawn directly via React elements without external data.