The presentation of the material in Blow Job is, once again, "anthological"—a mirror image, so to speak, which presents demands on our attention that are entirely without regard for that image's relation to the dialectic of the story. One of these demands arises through the use of the actor….
The lengthy (35 minute) blow job is accented by the paucity of expression demonstrated by the beautifully inept actor. Like the protagonist of other Warhol films, he is left to his own devices and since he is obviously either incapable of or uninterested in coping with the situation he finds himself in a fairly ludicrous position. In this sense the actor becomes an element or tool used in such a way never before considered in the film. This is another example of Warhol's formidable ability to extend and redefine reality—a preoccupation intrinsic to art. (p. 20)
Sex isn't plainly illustrated. Neither are sexual parts, acts or movements. Except for a bit of leather jacket which occasionally appears on the screen, the actor is as without identity as is the act. It is neither a homosexual nor heterosexual incident but rather personal, human and catholic….
The length of the film—of the blow job—is exaggerated probably to clarify the artist's dedication to the time element, as time is possibly the one most important element distinguishing the film medium from the other fine arts. And, if in most films, events are telescoped so that lengthy acts often appear much shorter on the screen, in a Warhol film they often appear longer, in their transition from actuality to the reality of the medium….
If the medium and message are to be considered as one, the films of Andy Warhol are the best illustration of the concept popularized by Marshall McLuhan that the medium is the message. The deliberate recognition of the message = medium idea may partially explain why it is hardly necessary to see a Warhol film. There is little to see that can't be adequately described. (p. 21)
Gregory Battcock, "Notes on 'Blow Job': A Film by Andy Warhol," in Film Culture (copyright 1965 by Film Culture), No. 37, Summer, 1965, pp. 20-1.