Though Mr. Lapham is trying to rein in Johnny’s pride, this passage reveals that he’s also a big reason why Johnny is so prideful to begin with—he’s not very good at managing his shop, and Johnny has to step in where his master falls short. However, it’s also clear that Johnny was likely prideful before he got all this extra power; he’d perhaps be like this no matter what. Further, that Johnny scolds Jehu highlights just how power-hungry Johnny is. Jehu is enslaved, so he has no power to argue with Johnny and defend himself. Johnny is picking on someone who can’t fight back at all, just to make himself feel better.