Let's make a face with D3.js!
A D3.js visualization assembles a smiling face from basic SVG shapes and animates the eyebrows in a looping motion. The example demonstrates fundamental DOM manipulation by creating a yellow circle, two eyes, rectangular eyebrows, and a mouth path using d3.select and chained append and attr methods. A 2000-millisecond transition sequence moves the eyebrow group vertically, illustrating D3's transition subsystem and the d3.arc helper for constructing the mouth's curved path.