Gilles Deleuze in Plato and the Simulacrum describes how Plato divides, what he calls the “domain of images” into two, on the one hand there are iconic copies, which are the true likenesses of the original, and there are phantasmic simulacra, which have a relationship of semblance to the original. The icons are endowed with resemblance, this is not a correspondence between two external things, but between a thing and an idea. “A copy truly resembles something only to the extent that it resembles the Idea of the thing.” The copy to be recognised as such will be seen as being endowed with the quality of the original. In short, it is the superior identity of the Idea that grounds the good claim of the copies, grounding it on an internal or derived resemblance. The copy can be understood as what is seen in the inner reflection of dianoia.
The claim of the simulacrum is “made from below without passing through the Idea.” Thus it is an image of the original, but without resemblance, it is without the quality of the original. It is there as an aesthetic image, i.e. it is perceived and as such gives an effect of the original. It is constructed not on resemblance but on “disparity” and “difference.” The simulacral image avoids “the equivalent, the limit, the Same, or the Like.” Making the simulacrum like what it is an image of represses it, confines it “within a cave in the bottom of the ocean.”