The Mouse Follower example demonstrates real-time interactive feedback by rendering a single circle that tracks the cursor’s position across an SVG canvas. Built with React hooks (`useState`, `useCallback`), it updates the circle’s `cx` and `cy` attributes on every `mousemove` event, using D3 v7 for SVG manipulation. The visualization overlays a large yellow circle with black stroke as a static background, while the moving circle responds dynamically to pointer coordinates, highlighting coordination between React state management and D3’s SVG rendering.