This animated SVG face uses D3.js v7 to build a cheerful character from basic geometric shapes. It draws a yellow circle head with elliptical eyes, circular irises, rectangular brows, and a mouth shaped using the `arc` function. The eyebrows are the only animated elements, moving via chained `transition` calls on their transform attributes. The markup is generated imperatively through `select` and `append`, with coordinates calculated from the SVG’s width and height attributes.