The grieving Achilles, shown lying prone here as if he himself were a corpse that needed to be mourned, is now held by the head from behind by her lamenting mother Thetis, Ι.18.071. This gesture re-enacts what typically happens at a real wake: the primary mourning woman will hold the head of the corpse from behind as she sings her song of lament. As we will see at I.24.724, such is the stance of Andromache when she cradles the head of her husband’s corpse while she sings her lament for him. See the comment on I.24.720–776. And the act of mourning performed by Thetis for Achilles here in Iliad 18 actually prefigures what will happen at the funeral of Achilles, which is of course not shown in the Iliad. At that funeral, which is shown only toward the end of the Odyssey, the corpse of Achilles will lie in state, and he will be mourned then by Thetis together with her Nereid sisters, O.24.058–059. Earlier in that narrative, as the corpse of Achilles is first seen lying in the dust after his death in battle, he is described there as larger than life in size, O.24.040: ‘you lay there, so huge in all your hugeness’ (κεῖσο μέγας μεγαλωστί). So also Achilles here in the Iliad is now being pictured as lying in the dust, and he is described here too in the same way, I.18.026–027: ‘all stretched out, so huge in all his hugeness, he lay there’ (μέγας μεγαλωστί τανυσθεὶς | κεῖτο). So, Achilles is already being prefigured here as a corpse that is larger than life.