This example builds an animated smiley face using D3.js, demonstrating fundamental DOM manipulation with SVG elements. It loads population data from a CSV file using `d3.csv` and binds it to rectangles via `data().enter().append('rect')`, though the visual face itself is constructed from SVG shapes. The code uses D3 v5 with `select` and `csv` imports, setting fixed rectangle dimensions of 300×300 pixels. The rendered SVG is 960×500, with the face representing population values for eight countries, though the interactive eyebrow movement hinted in the README is not yet implemented in the visible code.