A smiling face is rendered as a yellow circle with two eyes and a curved mouth, centered on a dark blue background. The visualization is built with D3 v5, using the `select` function to target the SVG element and `append` to add each shape. The mouth is drawn with the `arc` function, which defines inner and outer radii along with start and end angles. The SVG canvas size is set to the window's dimensions, and all face components are positioned relative to a translated group.