Repeated SVG smiley faces are generated in a grid, each drawn with a yellow circular background, two black eyes, and a curved mouth. The code builds these faces using React to compose separate components, including `FaceContainer`, `BackgroundCircle`, `Eyes`, and `Mouth`. The mouth shape is rendered using `d3.arc()`, which creates a path based on specified radius and angle parameters. Each face is rendered identically without variation in appearance, placement, or styling.