As I think has been pointed out already, Jimmy Corrigan is a very densely illustrated novel. There a many recurring visual themes and motifs that Chris Ware uses to various ends. Jared and Lars have already pointed out several including the shifts in the perspective distance. One thing that struck me as part of these visuals was the distinct lack of faces on non-Corrigan characters. Not even all of the Corrigan characters have faces.
We are given occasional faces, like Dr. Wilson and a few others, but more often than not the panels are arranged in such a way that you don’t ever really see the faces of other characters. You never see modern-Jimmy’s mother’s face at all, only the photo of her where she is turning away slightly from the camera. Often the faces are off-panel but they are frequently obscured by other objects or even by text balloons. So why don’t we get to see these faces?
I think there are multiple reasons, or potential reasons, for this visual motif. I think first and foremost it is part of Ware’s construction of this/these characters as isolated and distant from one another. These people are all unable to connect to one another and so everyone becomes just another faceless person. People are essentially just other objects.
Additionally, I think this motif is part of Jimmy’s character. Modern-Jimmy is socially awkward to the nth degree. Each panel with him is like a full episode of The Office. He is unable to really connect with anyone and is petrified of the very idea. He is incapable of dealing with the world outside of his imagination (and he isn’t even all that in control of that). But more than the awkwardness is his infantalization. He is a child in many ways and therefore doesn’t see people on an equal level, but must look lower down or away. I’m reminded of other comics or cartoons focused around children where adults are never depicted or are only shown from the knee down, like in Peanuts or Muppet Babies. Modern-Jimmy is an awkward man-child, while Past-Jimmy is an actual child, and the lack of faces seems to be a way of communicating that child perspective.
I think that’s a great observation and a well-reasoned explanation, Phineas! I would like to propose an additional possible reason for the obscured faces – perhaps it is a psychological aspect of Jimmy that he doesn’t look at people’s faces – possibly because of infantilism, but possibly also because of psychological conditions. I could easily see Jimmy as either somewhere along the autistic spectrum, or sociopathic and uninterested in people as people.