I really like the shift is word-choice given to each section, depending on the character it focuses upon. I've started to notice changes in word choice apparent during the sections dealing with the various different characters. While the narration is still obviously third person limited throughout, the tone in each is subtly altered, which seems to help personify the character. In J.'s portions the narrator tends to give a well read (through allusions to other literary works/authors, ranging from Hunter S. Thompson to William Shakespeare), as well as cynical and sarcastic. The tone seems more distraut, verging on total apathy, for Miggs, (except when it talks about stamps) and depressed, yet confused, and somewhat distressed for Pamela. While these changes are subtle, they help to make the characters come alive, and further diferentiate them.
This break typically is done by chapter, though in one interesting occasion, it breaks in the middle of the chapter, shifting from Pamela to J. (186) I beleive this is the only place where the prose is split by an entire line of space, rather than a simple indentation to begin the next paragraph. It is especially interesting as it shifts during a conversation between the tow of them where each is sizing the other up.