his very first comic!
The other thing that struck me was how similar the layout was to the illustrations of a book I had read recently about a two dimensional world called Planiverse by A.K. Dewdney. Here is the main character's home:
The novel had a similar concept as Flatland by Edwin Abbot. Both deal with what life would be like living in two dimensions. Just what you need for being prepared to be trapped in an XKCD cartoon for a day!