Despite its title, this example displays a grouped bar chart of U.S. state population data across age brackets, rendered as SVG. The chart uses `d3.scaleBand` for both state and age groups, with a `d3.scaleLinear` for the y-axis and `d3.scaleOrdinal` for color encoding. Animated eyebrow movement is not present; the code instead constructs the chart with D3's DOM-manipulation methods, including `selectAll`, `join`, and `.attr` calls to build the rectangles, axes, and legend.