A large yellow smiley face is drawn with D3.js, featuring two eyes, rectangular eyebrows, and a mouth created using the `d3.arc` API. The eyebrows animate vertically in a looping sequence using chained `transition` calls with a 2-second duration. The SVG scene is centered via a `g` element, with all shapes positioned relative to the viewport dimensions. The code demonstrates fundamental DOM manipulation through D3 selections and attribute updates.