A yellow smiley face rendered with React and D3 v7 draws a circle for the head, two smaller circles for eyes, and a mouth built using the `arc` generator. The SVG uses fixed pixel dimensions, with positions derived from `width`, `height`, and offsets like `eyeOffsetX` and `eyeOffsetY`, plus a stroke width for the face outline. The mouth arc spans from PI/2 to 3PI/2, creating a crescent shape, while the head’s radius is calculated from the SVG height minus half the stroke width. All shapes are drawn declaratively via React’s JSX, with D3 only supplying the arc path.