An animated smiley face drawn with SVG demonstrates reusable D3 features. Yellow circle, black-outlined head, and eyes are static shapes, while the eyebrows animate through chained `transition.attr` calls that move them up and down over 500ms intervals. The mouth uses the `d3.arc` generator, with a semicircular path defined by inner/outer radii and start/end angles. Coordinates rely on explicit SVG attributes, and the face is centered via a `translate` transform on a group element.