Let's make a face with D3.js!
A yellow smiley face with movable eyebrows demonstrates fundamental DOM manipulation with D3.js. The code selects an SVG element and builds the face from primitives: circles for the head and eyes, rectangles for the eyebrows, and an arc-generated path for the mouth. Using D3's selection and transition methods, the eyebrows animate vertically over two seconds, then return, cycling through the eyebrow group's transform attribute. The example relies on d3.select, d3.arc, and chained transitions to compose and animate SVG shapes.