A React-based SVG visualization renders a single yellow circle that follows the mouse cursor across the full browser window. The circle’s position updates live via React state and the `onMouseMove` event handler, which captures `clientX` and `clientY` coordinates. Using the `useState` and `useCallback` hooks from React 16.9, the component re-renders the SVG circle on every pointer movement, demonstrating declarative interaction with mouse input in a minimal, single-element graphic.