A smiling face drawn with SVG shapes animates its eyebrows in a loop. The example demonstrates basic SVG elements—circle, rect, and path—styled with CSS and manipulated through D3 v5 selections and transitions. The face is centered using SVG transforms, with the mouth generated via `d3.arc` as a half-circle path. Eyebrows alternate between two vertical positions using chained `transition().duration(2000)` calls, creating a playful wink-like effect. All rendering is static SVG with animation handled purely through D3’s transition system.