The excerpt from "The Song of Achilles" presents a nuanced portrayal of Achilles' internal conflict, suggesting that his decision not to attack Agamemnon stems from his own reasoning rather than divine intervention. This builds on the idea that Achilles is capable of exercising his own judgment, as he weighs the consequences of his actions and chooses to withhold immediate violence. The struggle on his face indicates that the choice is significant and personal, perhaps reflecting a desire to inflict greater punishment through the outcome of war rather than a swift act of vengeance.
Therefore, the correct interpretation would be that it shows that Achilles made his decision without meddling from the gods. While the presence of the gods often influences the actions and fate of characters in classical mythology, this passage emphasizes Achilles' autonomy and the weight of his decision.