... Now ...
look at how the painter is looking: it is right at the subject he is painting, at once, it is right at us.
“The spectacle he is observing is thus doubly invisible” (443), for it is out of the frame of the painting, and it is right at us, that ‘self’ which we lose sight of as soon as we look at something—yet, we can’t fail to see this invisibility.
The back of the canvas we see—seeing nothing of the painting on canvas on which he is painting—“reconstitutes in the form of a surface the invisibility in depth pf what the artist is observing” (the canvas’ first function of the back of the canvas).
His line of sight transgresses the frame of the actual painting to connect to us, “and links us to the representation of the picture” (444).
And opposite behind this lightened line across the painting’s forefront, there is a wall of paintings, with one standing out brighter: a picture that is not a picture, a mirror … illuminating two subjects … “fulfills its function in all honesty and enables us to see what it is supposed to show” (446): the subjects of the painter’s (hidden) painting … “Of all the representations represented in the picture this is the only one visible; but no one is looking at it” (446)—it is behind the backs of all the subjects in the painting, but shows us the subjects of the painting’s painting.