An animated scatter plot cycles through four Iris dataset variable pairs every two seconds, revealing different correlations between measurements. Each circle represents a flower sample, with axes rescaling to the current variable selection. The reusable chart module updates its x-value accessor while preserving the same SVG rendering. D3's `scaleLinear`, `axisLeft`, `axisBottom`, and data joins create the idempotent visualization, with `setInterval` driving the sequential column switching.