Ahh, you beat me to it!
I too was flipping through yesterday's comics and saw the same strip. You know, it was a very accurate depiction: venting holes, mouse, side input panel, the shape and coloring, etc. I was impressed!
The artist probably uses one, that's why.
Also, on the opposite page (in the San Diego Union-Tribune) was a comic strip called "Adam @ Home" and yesterday it showed the main character sitting in front of his PC in a state of obvious frustration. Then he told it if it didn't behave, he would trash it and "get one of those multi-colored computers" everyone's using now. Then the computer replied that he couldn't because "I cancelled your credit cards" or something like that.
Two iMac references in the same comics page in one day! Very cool...
Photoshop rocks...but Illustrator rules!
iMac DV (384MB RAM, OS 9)