This example visualizes penguin bill dimensions using a scatter plot, with bill length on the x-axis and bill depth on the y-axis. The chart uses D3.js v7 APIs such as `scaleLinear`, `extent`, `axisBottom`, and `axisLeft` to render axes and circles for each data point from the `@curran/penguins` dataset. The visualization follows an idempotent rendering pattern, where the `viz` function calls `scatterPlot`, which in turn leverages the `axes` utility to manage chart structure and labels.