A yellow circle follows the mouse cursor across a full-screen SVG canvas. The visualization demonstrates a simple interactive state update in React, where the circle’s position mirrors the cursor’s coordinates in real time. The component uses React’s `useState` hook to track the mouse position and `useCallback` to handle the `onMouseMove` event, updating the circle’s `cx` and `cy` attributes. The SVG rendering is driven entirely by React’s declarative updates, with no additional data source or animation library involved.