A cheerful animated face built entirely from D3.js SVG primitives, with eyebrows that raise and lower repeatedly via chained `transition` calls. The code constructs a yellow circle, two eyes, rectangular brows, and a mouth drawn with the `d3.arc` generator, then animates the eyebrow group’s transform over two-second intervals. The example demonstrates basic SVG shape composition and sequential transitions using d3-selection and d3-shape functions.