It's not really a surprise, this late in Infinite Jest--some hundred-odd characters later (and almost all of them somehow feeling fully realized, even in cameo)--and with an equal number of usages of the word "putative" and the concept of apres-garde filmmaking's distorting lenses, to say nothing of the plain old down-on-the-knees belief being borne out of the AA sections, but yes, it's safe to say that things aren't entirely as they seem.
It's somewhat fitting, then, to start with Apparitions (p. 714 - 729). Kate Gompert sees Poor Tony as "the most unattractive woman"--and by all means, he most certainly is at this point--but let's not discount P. T. Krause's own viewpoint: to him, Ruth van Cleve, in hot pursuit of her hot purse, is "the wretched creature." And then, too, there's Randy Lenz, who
wore fluorescent-yellow snowpants, the slightly shiny coat to a long-tailed tux, a sombrero with little wooden balls hanging off the brim, oversize tortoise-shell glasses that darkened automatically in response to bright light, and a glossy black mustache promoted from the upper lip of a mannequinand yet still looks down on the Orientoid or Chinkette women and their "monkey language." This man who can still whisper to himself "Jesus what a lot of fucked-up ass-eating fucking losers." It's Poor Tony, ultimately, who ends up shouting "Help!" and "Please!" as he flees the pursuant scene of the crime, and--remaining true to that double-sided coin of opposites that Wallace has been flipping throughout the novel--no surprise that a cry of "Stop!" and a counter of "Go" are what end this section.
There's more of the same when Remy Visits Ennet House (p. 729-735, 747-755), and we're cued in by the recollection two now sober--okay, soberer--women have of their Divinely Chosen's Love Squad cult, a cult which one assumes at one point made perfect sense to them, but which now in retrospect, seems a totally alien thing. Bear in mind that Wallace begins his novel in the Year of Glad, which makes the entire rest of the novel a retrospective, an idea that somewhat supports my last-minute supposition that Hal, at the novel's start, fucked up as he is perceived to be, is actually at his sanest, most lucid point. Mario wonders, later on, whether or not sadness can make a person act "himself even more than before a sad thing happened" (p. 768); in that light, couldn't a narcotic, depending on where you're standing? (And don't think I haven't noticed how this lower-cased usage of "himself" sheds some appropriately reflexive light on their nickname for J.O.I., that is, Himself.)
Add to this sense of perception the thought of distance, and now we're getting closer to the truth of it, because for all our platitudes, it's not so much the walking in another's shoes that's the important part--it's the seeing in another's mind that sets us apart. Joelle Behind the Camera (p. 736 - 747) is interesting in this light: she's entirely able to dissect Orin's messed-up childhood (including Avril's possible molestation of Orin-as-child) and to find the heart of Jim's early oeuvre, and yet she can't confront her own personal Daddy issues. And what was James's goal? "Freedom from one's own head, one's inescapable P.O.V.," which, to be fair, a microwave oven would achieve.
And hey, here's the sad irony--what Molly Notkin claims Joelle felt guilt about later was for forcing Jim to lay off the sauce, as the loss of that diluting agent seems to have forced him to take a more permanent mental vacation. Of course Madame Psychosis prefers to be behind the camera--"She'd do the capturing, thank you very much" (p. 739). It's a great way to avoid behind imprisoned by it. Actually Notkin and Psychosis are both correct: J.O.I.'s work is "like conversing with a prisoner through that plastic screen using phones" and "like a very smart person conversing with himself"; all that means is that dear old Himself was depressed by the realization that a part of him was held prisoner within himself.
Mario Behind the Camera (p. 755 - 774), on the other hand, is a very different creature. It's hard to tell at first, as he speaks much like all the other characters, which is to say that he seems not to be really responding to the other person, so much as he is following his own train of thought. But while Hal pegs him as sounding sort of like Avril, he also acknowledges that "with you, I can feel you mean it" (p. 772). This is a form of perception, too, and it's the one that divides that narrow line between Avril's creepy simulacra-like assertions of love ("I am right here with my attention completely focused on you," p. 763) and Mario's less direct but more comprehensive connection to what sadness really is. (A thing which Avril can only define--and not for nothing is she a militant grammarian.)
The thing about this form of perception--a perception formed of language, and which can dangerously turn to visual Muzak (as in the Q.R.S. building some pages hence), and just as easily simply be filled with lies, lies that a wisening Hal understands are what create the real monsters. It's what Todd Possalthwaite Realizes (p. 787's footnote #324), i.e., that "nothing's true." A sub-set of this is the experience the E.T.A. 16s face: "Am I true?" (p. 1071), a phase in which, it's important to note, Hal started to ingest drugs on a daily basis, trying to define that Hal-shaped hole inside of himself, the sort of empty hole one gets not simply from not being dandled enough as a child (as Kevin Bain nightmarishly assumes), but from being lied to on a continual basis.
This here's the crux: what destroys all of these characters, or deforms them, is not anything actually real, not really. It's simply perception that overwhelms them, or redefines them, or changes them. Assuming that Joelle is actually scarred by the acid (which assumes that the Thanksgiving story related by Molly Notkin is actually true), is it that which deforms her? Or is it Orin's reaction to her? By wearing a veil, one removes the potential for perception, and creates, in its place, a sort of Schroedinger duality (and it's a great way for Wallace to create that infinite space, by allowing opposites to co-exist): Joelle is both scarred and perfect.
Perception has dangerous physical connotations, too. This section ends with two (or three) explosive shifts in perception: Joelle's (or is it Lucille Duquette's, according to p. 795) father abandons the world of infantilizing silence that he'd created, and in doing so, writes a different reality upon the old one. Nothing has actually changed--if anything, everyone is just confirming what they already knew--and yet by facing it, Joelle's Thanksgiving (p. 787 - 795) really goes to shit. A similar experience occurs--accidentally--when John Wayne (p. 795's footnote 332), dosed with tenuates, unloads all of his internal thoughts. (Similar to how a drunk can sometimes be an entirely different person, which may explain why Jim drinks so much.) John hasn't changed at all as a person--he's always been this hateful--and yet to everyone else, he's somehow a new man. How odd, the way the world works.
And how interesting (and sort of sad) to read this book freshly, for the first time (sad because it will never be virginal again), finding my perception shifted again and again. But in honor of my original perception of this novel, way back in my first Jestational post, let me briefly revisit the theme of infinity. Is there any doubt that David Foster Wallace, by shifting perceptions with every page, has managed to make the novel infinite after all? To use a tennis metaphor, imagine the way in which the court is limned by boundaries: there are still an infinite number of ways to hit the baseline, always getting a little closer to that limit between out-of-bounds and in, but never quite crossing it. Now add to that infinite number of moves an expansion of the court--a fresh way of perceiving the court (for instance, the transition between singles and doubles) and you've opened up another infinite set of moves. Shift that perception once more, and again, and again, and, well, you see where this is going. Or rather, you don't: it's infinitely far away, even as the end nears.
PS. As to whether or not Joelle's the Medusa or the Odalisque, we may never know. But I find myself continuing to lean toward the latter: we are talking about improbably deformed people, and a simple Two-Face-like disfigurement is hardly unbelievable.