ὑπόδρα ἰδών is another formulaic facial expression that is part of speech introductions (compare 10.400). This look is given at least twenty-six times in the two epics, twenty times within the formula τὸν/τὴν/τοὺς δ᾽ ἄρ᾽ ὑπόδρα ἰδὼν προσέφη + epithet + name (thirteen times in the Iliad, seven in the Odyssey, Holoka 1983:3n6; Beck 2005:34, 284). Holoka, quoting Stanford, asserts that “The actual facial expression signified by ὑπόδρα ἰδών is quite unmistakable: ‘looking (out) from beneath (scil. beetling or knit) brows’,” and also cites research on facial expressions for the “distinctiveness of this positioning of the brows as a universally recognized sign of anger” (1983:4n8). That anger, Holoka argues, is a reaction to what the previous speaker has just said. In sum, Holoka argues: “In both Homeric epics, to look darkly is to employ a nonverbal cue fraught with judgmental significance. The speaker, whatever his message, transmits by his facial demeanor that an infraction of propriety has occurred … In all instances, the facial gesture ὑπόδρα ἰδών charges the speech it introduces with a decidedly minatory fervency and excitement: a threshold has been reached and such inflammable materials as wounded pride, righteous indignation, frustration, shame, and shock are nearing the combustion point” (1983:16). Holoka is focusing especially on the cases (twelve times in the Iliad) in which this look is given by one comrade (often a superior) to another (often a subordinate), and he says that the situation with Dolon is a different case because it is between enemies (1983:8).
In fact, the most telling parallels for this fierce look of Diomedes at Dolon come from the Odyssey, where Odysseus gives this look to the suitors, either individually (Odyssey 22.60, 22.320) or as a group (Odyssey 22.34), as well as to Iros (Odyssey 18.14) and the disloyal slave Melantho (Odyssey 18.337, 19.70). (These last two are exceptional in that the look is given to a woman; other than Zeus looking at Hera this way, all those who receive the expression are male. But the formula is flexible in accommodating the gender change.) These looks given to the suitors show both contempt and suspicion, anger and fear, and we can see this same mix of emotions in the words of Diomedes that follow this instance. Both Diomedes here and Odysseus in Odyssey 22 follow up this look at an enemy with beheading him. In the Odyssey, Odysseus gives this look to Leiodes, the suitor who, as we hear upon his introduction as the first to try the bow (Odyssey 21.144–147), had found the reckless deeds of the suitors hateful and felt righteous indignation toward them. It is this man who supplicates Odysseus; Odysseus rejects his plea for mercy and beheads him (see also below on 10.456–457). Given to an enemy, then (and we can add that Achilles gives this look to Hektor three times at Iliad 20.428, 22.260, 22.344), this look carries with it a danger of sudden violence: the combustion point is not merely approached, it is quickly reached. So here also we see the flexibility of the formula within its context: the essential meaning of the expression is maintained, but the expectation of what will follow is shaped by whether the look is given to a comrade or to an enemy.
As we saw above on 10.400, these telling facial expressions are sometimes absent in other versions. Allen’s (and subsequently, West’s) papyrus 90 (Oxyrhynchus 6.949) has the possible multiform [τον δ ημειβετ επειτα βοην αγα]θος Διομηδης. See 10.283 for more on this multiform.