A smiling face rendered in SVG is centered and built entirely with D3.js shape primitives. The static face consists of yellow circles for the head and eyes, black strokes, and a donut-shaped mouth path created with the `arc` generator. An animation is driven by chained `transition().duration(2000)` calls, which move the two rectangular eyebrows up and down in a repeating cycle. All elements are appended to a group translated to the SVG center, using explicit pixel coordinates for positioning.