What we have here is a fabricated circuit diagram that is made up of dozens of visual puns. Most of these puns are merely everyday objects that would normally not be seen in such a diagram, causing the reader to think “that would never be there, that does not make sense” and laugh (e.g. a squirrel). There are also many references to the components of a circuit diagram looking like other things, such as freeways and sandals. The remainder of the jokes are references to geek and engineering topics and also two sexual jokes.
The purpose of this comic is to appease the computer and electrical engineering students who have felt their particular geek sub-culture has been left out of the comic strip recently.