This looping scatter plot animates between two views of U.S. city demographics, alternating between circular and triangular/square markers. The visualization compares population against GDP per capita, with color coding indicating which metric is larger. Built with D3.js v7, the example loads CSV data, computes linear scales, and toggles between two SVG charts using symbol generators. Axes and legends are drawn separately for each view, with the display switching via the `style.display` property.