A smiley face is drawn using SVG shapes within a React component, with a yellow circle for the head and two smaller circles for eyes, all centered and scaled to the browser window. The code uses React's `createElement` via JSX and `ReactDOM.render` to mount the component, and it relies on the React 16.9 UMD builds loaded from a CDN. The rendering is purely SVG, with the face positioned through a translated coordinate system based on window dimensions.