A smiley face rendered in SVG follows the cursor inside a 960×500 viewport. The React component tracks mouse movement via the `onMouseMove` handler and updates the circle’s position using state and the `useCallback` hook. The face is drawn with a yellow circle and two black eye circles, though the eyes remain static while the entire group moves. Rendering relies on React DOM with SVG elements, and the example highlights state-driven updates without external data sources.