for Pound, an 'image' is "that which presents an intellectual and emotional complex in an instant of time" (see Pound, "A Retrospect")
Hejinian: "for Oppen, that instant is an indexical event" (88)
Mary Ann Doane: indexicality is "the imprint of a once-present and unique moment"
Hejinian refers to "[t]he indexically at hand, the present, palpable instant"
see Doane's The Emergence of Cinematic Time
Doane, elsewhere, confirms that she means "indexical" in the sense that semoitician C. S. Peirce means it: "Within Peirce’s taxonomy of signs, the power of the index is a denotative one, forcing the attention to a particular object, here and now. Indices are characterized by a certain singularity and
uniqueness; they always refer to individuals, single units, single collections of units, or single continua. They are dependent upon certain unique contingencies: the wind blowing at the moment in a certain direction, a foot having landed in the mud at precisely this place, the camera’s shutter opening at a given time. Unlike icons, indices have no resemblance to their objects [...] the index is evacuated of content; it is a hollowed-out sign. It (for instance, a pointing finger) designates something without describing it"
"Unlike icons and symbols, which rely upon association by resemblance or intellectual operations, the work of the index depends upon association by contiguity (the foot touches the ground and leaves a trace, the wind pushes the weathercock, the pointing finger indicates an adjoining site, the light rays reflected from the object 'touch' the film)"
"Indices 'furnish positive assurance of the reality and the nearness of their Objects' (Peirce 25). But they are limited to the assurance of an existence; they provide no insight into the nature of their objects; they have no cognitive value, but simply indicate that something is 'there.' Hence, the 'real' referenced by
the index is not the 'real' of realism, which purports to give the spectator knowledge of the world. The index is reduced to its own singularity; it appears as a brute and opaque fact, wedded to contingency—pure indication, pure assurance of existence"
An indexical poem could, presumably, do this