This example shows a yellow smiley face drawn with SVG circles in React, where one circle follows the user’s mouse movements across the screen. The face includes two static eyes and a large yellow head with a black outline, while the nose moves dynamically. It uses React’s `useState` and `useCallback` hooks to track mouse coordinates via an `onMouseMove` event handler, re-rendering the circle’s `cx` and `cy` attributes. The visualization is built with React 16.9 and rendered as SVG, with a fixed canvas size of 960 by 500 pixels.