Boat Painting

This is just a simple painting on the wall of the moon's hospital—probably not great, either, like some sort of hotel art—but Titus can't keep his eyes off it. Check out how he describes it, twice:

One [of the walls] had a picture of a boat on it. The boat was on a pond or maybe lake. I couldn't find anything interesting about that picture at all. There was nothing that was about to happen or had just happened. (8.2) 

I couldn't do a f***in' thing except look at that stupid boat painting, which was even worse, because now I saw that there was no one on the boat, which was even more stupid, and was kind of how I felt, that the sails were up, and the rudder was, well, whatever rudders are, but there was no one on board to look at the horizon. (10.7)

Something about this painting really gets under Titus's skin. Part of the problem is that Titus (as well as his friends) suffers from a distinct lack of curiosity. He's so used to insta-gratification and over-stimulation that this painting seems like a personal insult. 

It also brings out Titus's self-centeredness. Part of what he hates is that there's no one there to "look at the horizon." He just can't appreciate this simple scene of nature. This could be because it's completely alien to him; he's never seen a body of water that doesn't look like a pile of steaming toxic goo.

Come to think about it, maybe the painting symbolizes the pristine nature that Titus's world has lost—and Titus would rather just not think about that.