A D3.js example assembles a smiling face from primitive SVG shapes: a yellow head circle, two eye circles, rectangular eyebrows, and a mouth formed by an annulus arc path. The scene is vertically centered using a group translation, and the right eyebrow demonstrates the library's chained transition API by animating its vertical position in two sequential 2-second movements. The code imports `select` and `arc` from D3 v5 and applies SVG attributes directly within a React-based build.