The question that has dogged my reading of psychoanalysis is that of the political - when we read Freud's famous quotes that (paraphrasing) the goal of psychoanalysis is to change dysfunctional mental illness back into everyday human misery, or that the universality of civilization will mean the omnipresence of neurosis, are we hearing a lament, or a sanguine acceptance? Are the processes of repression, civilization, and symbolization described by Freud and Lacan universal constants to whose pains we must resign ourselves in exchange for greater benefits, or are they open to challenge?
Zerzan himself has some very clear positions on all of this (and is clearly strongly influenced by psychoanalysis, particularly Freud), but for now I just want to stick to the "Mirror Stage" as I warm up to class. I think that (despite Lacan's notorious opacity) there are points where it is clear he is quite critical of the process of socialization he's describing - certainly, more clearly critical than Freud ever was. Some of these are subtle, almost poetic - for instance, the description of the assumption of the specular self-image (that is, the leap to figuring out that thing in the mirror is me) in terms of putting on armor, or of a quest to enter "a lofty, remote inner castle" - martial imagery that doesn't bespeak a happy life.
Lacan occasionally suggests the situation might be constitutive and unavoidable, but even then he's quite clear that it's unpleasant. As he puts it, "the mirror stage is a drama whose internal thrust is precipitated from insufficiency to anticipation" - that is, from the fragmentation of the infant's experience to the adult's constant desire for a return to "wholeness" that will someday be achieved. But in that same passage, Lacan uses a crucial term - alienation, which he uses to characterize the assumption of the body in the mirror as one's own. Particularly given the essay's genesis after Horkheimer and Adorno's Dialectic of Englightenment, it seems safe to guess that Lacan used this term quite knowingly.
Perhaps Lacan's perspective shifted by the time of May 1968, when he would be accused of being a counterrevolutionary. But at least in this essay, it seems he was doing work that was, more than most people tend to grant, well athwart the progress of history, capital, and the mediatized world we now live in.