This example shows a yellow smiley face rendered as a circle with two black eye circles, centered on a full-screen SVG. The React app uses `window.innerWidth` and `window.innerHeight` to set the drawing dimensions, and translates a `<g>` group to the center before positioning features with offsets. It employs React 17 and `ReactDOM.render` to mount the SVG, with hardcoded constants for eye placement and radius, while the mouth remains unrendered. The face updates responsively by recalculating dimensions from the browser window.