This example displays a smiling face constructed from SVG shapes, including a yellow circle, two eyes, and a mouth path with a curved arc. Built with React and D3.js v7, it uses the `arc()` function from d3-shape to generate the mouth with specified inner and outer radii and angles. Positioning is handled through SVG transforms, with the face centered on an 960×500 viewport. The code demonstrates proportional sizing by calculating radii relative to the center coordinates and stroke width.