A yellow smiley face is drawn in SVG with D3.js, featuring a circular head, eyes, eyebrows, and an arc-based mouth with a tongue. The demonstration focuses on fundamental DOM manipulation by using D3 selections to append and style shapes, then applies a repeated transition to the eyebrows’ `transform` attribute, making them bounce up and down every two seconds. The code imports `select` and `arc` from D3 and sets the SVG dimensions from the markup attribute.