Good software is intuitive. Leveraging one’s pre-existing knowledge of the physical world can be useful formaking a software application more comfortable for the user. More literature on that here. I’ve worked with IDEO on a few pieces of software and seen this physical pattern in their designs more than once:
When I look at that sketch; I see the designer’s intention and I think that arrangement of elements in a clump is natural, but what an unbearable pain it is to make that happen with HTML! There’s no magic CSS for
display: in-a-pile;… until now!