This example builds a cartoon face as a yellow circle with eyes, eyebrows, and a mouth, all rendered in SVG. The eyes and eyebrows are positioned using D3 selections and attributes, while the mouth is drawn with the `d3.arc` shape generator. The eyebrows animate upward and back down over two 2-second transitions, demonstrating `transition.attr`. The face is centered via a translation and styled with CSS on the `body`.