A grid of 105 circles is drawn across the viewport, each positioned according to its index in the sequence. The example demonstrates D3's selection API by using `select('body')` and `selectAll('circle')` to append SVG circles with computed `cx` and `cy` attributes. Instead of relying on layout methods like `join`, it manually chains `data()` and `enter()` to populate the visualization. The code uses D3 v6's `range` to generate the data array, assigning each circle a fixed offset. The SVG rendering fills the entire browser window, with the circles arranged in a diagonal pattern.