This example demonstrates how React state manages asynchronously loaded data in a visualization. It fetches a CSV file of CSS named colors using D3’s `csv` utility, storing the parsed result in React’s `useState` hook. While the data loads, the interface displays “Loading…”, then renders a text summary showing the file size in kilobytes, row count, and column count using `d3.csvFormat`. The code integrates React hooks like `useEffect` and `useCallback` with D3 v5 to bridge data processing and component rendering.