Let's make a face with D3.js!
This example constructs a cartoon face from primitive SVG shapes: a yellow circle for the head, two circles for eyes, rectangles for eyebrows, and a semicircular path for the mouth. Animated with D3.js v5 transitions, the eyebrows move down and up over four seconds, creating a simple expressive gesture. The code uses `d3.select`, `d3.arc`, and chained `.transition().attr()` calls to build and animate the face within an SVG canvas.