A grid of 18 smiley faces rendered in SVG, each with a yellow circle, black outline, and two eyes, demonstrates parameterized React components. The faces vary randomly in eye radius, using D3’s `range` to generate the array of instances. Built with React and D3 v7, the visualization uses `d3.arc` to draw each mouth as a curved path, with all elements assembled via custom components like `FaceContainer` and `Eyes`.