Let's make a face with D3.js!
This example demonstrates fundamental DOM manipulation with D3.js by constructing a cheerful yellow smiley face from SVG primitives and animating its eyebrows. The code uses `d3.select`, `d3.append`, and `d3.arc` to build the face's circles, rectangles, and mouth path within a centered group. A `transition` with a two-second duration moves the eyebrow group up and down, creating a looping eyebrow-raising effect. The rendering is entirely SVG-based, with coordinate calculations in plain JavaScript driving the layout.