Comment by ajanuary

It loads a json file [1] that contains the co-ordinates of the tip of each point and the corresponding image. It uses this to create a Voronoi diagram [2] using a "custom Javascript implementation of Steven J. Fortune's algorithm" [3].

[1] http://www.pointerpointer.com/gridPositions.json

[2] http://en.wikipedia.org/wiki/Voronoi_diagram

[3] http://www.pointerpointer.com/js/rhill-voronoi-core.js