A smiling face made of sky-blue SVG shapes demonstrates basic D3.js DOM manipulation. The code uses `d3.select` to append a circle for the head, two circles for eyes, and an arc-generated path for the mouth. Eyebrows are rectangles that animate vertically through chained `transition().duration()` calls, moving down and back up. The example relies on D3 v5's `select`, `arc`, and transition methods, rendering entirely in SVG with no external data.