A smiling face is drawn with D3.js (v6) using SVG shapes: a yellow circle for the head, two circles for eyes, rectangles for eyebrows, and an arc path for the mouth. The eyebrows animate upward and downward via chained `transition` calls, creating a repeated eyebrow-raising effect. The code imports `select` and `arc` from D3, uses SVG attributes for positioning, and centers the face by translating a group element based on the SVG’s width and height.