Helen, as we saw, speaks of herself as a “statue” (agalma) (262), and the same word is used for her double (705, 1219). Similarly, when Theonoe calls the double a mimēma, or artistic “imitation” (875), she is echoing language used earlier by Teucer when he first lays eyes on Helen. Believing her to be a stranger, he calls her “the murderous image of a woman” — which correctly describes the eidōlon — and perceives her as an “imitation” (mimēma) of the Helen who was fought over at Troy (72–75).
He sees her, that is, as the double’s double. The Helen on stage is, in fact, as unreal as the eidōlon, even though she too moves, speaks, and acts (in more senses than one). Whereas her double is a divinely sculpted figure, Helen’s fictitiousness is that of a masked and costumed actor “sculpted” by the playwright. As a literary construct, she is a “double” of her poetic antecedents, her virtuous persona parasitic on the adventures of her twin.
Ruby Blondell, Helen of Troy: Beauty, Myth, Devastation