A smiling face rendered as a yellow SVG circle with black outline, black eyes, and a gap for a mouth, centered in the browser window. The face uses React’s `useState` hook to track the mouse position, updating on every `mousemove` event, though no visual change tied to that position is implemented. The SVG dimensions and face element positions derive dynamically from `window.innerWidth` and `window.innerHeight`, with React rendering the final markup via `ReactDOM.render`. The example demonstrates a static geometric illustration with event-handling logic in place.