This example demonstrates how to load a CSV dataset into a React application using D3’s `d3.csv` method, then display a summary message about the fetched data’s length and size in kilobytes. The React component `App` manages state with `useState` and `useEffect`, triggering the data fetch asynchronously. The message is computed by a helper function that relies on `d3.csvFormat` to measure file size. The SVG-rendered smiley face is commented out, so the visualization focuses purely on the data-loading workflow.