A yellow circle follows the mouse cursor, moving responsively across a full-window SVG canvas. The React-based application uses the `useCallback` hook to refine mouse-move event handling and `ReactDOM.render` to update the circle’s position. It relies on SVG’s `onMouseMove` event and absolute coordinates via `clientX` and `clientY` to track pointer movement. The visualization demonstrates a minimal, real-time interactive pattern with no external data source.