This example animates a smiling face, constructed from a yellow circle head, two eyes, eyebrows, and a mouth, against a black stroke. The entire face is centered within an SVG canvas using a D3 translate transform. The code relies on D3’s `select` and `append` to build the SVG structure, and the mouth is drawn with a `d3.arc` path. A two-second `transition` sequence shifts the eyebrows up and down, creating a surprised or winking expression on the static face.