A grid of nested circles and rectangles animates into place on an SVG canvas. The visualization builds a parametric layout of 91 cells, each containing concentric circles with decreasing radii and a grey rectangle that expands during the transition. The code uses D3 v5 selection and range modules to generate and position elements, with the `transition().duration()` API animating the circles from the center outward and rectangles from zero size. Hover effects change fill colors to black.