A yellow smiley face follows the mouse cursor across an SVG canvas, redrawing its position on every mouse movement event. The face is built from reusable React components—a yellow circle background, two black eye circles, and a mouth drawn with `d3.arc()`—all composed within a `<g>` transform. React state tracks the cursor’s `clientX` and `clientY` coordinates, triggering re-renders via `useState` and `useCallback`. A dropdown menu is present but not connected to the visualization.