Myth and imagery
The poem suggests through imagery that Judith was divinely appointed to her fate, and that victory was handed to her by fateful coincidence, as if the point of the story was to create a myth about God's function as a deliverer of the oppressed and an opponent of the powerful patriarchy. This myth illustrates through imagery what justice looks like. The myth is a specific response to rape, because the story's first image is a man using his power to make a woman give herself to him under the threat of death.
Entitlement and pleasure
The imagery associated with a broken patriarchy is that the king uses his authority to exploit others for his own pleasure. The depiction is of entitlement, because he feels entitled to rape, and because he feels uniquely entitled to power, as if power cannot be taken away from him. This is shown through his indulgent relationship to alcohol. By drinking himself stupid, he is daring the universe, because alcohol takes away his agency. The portrait is of an infantile, entitled kind of power that deserves to be usurped.
Simple victory
One might think that it would be very challenging to overthrow a powerful government with a sovereign tyrant, but this story shows that actually, victory is very easy when it is divinely appointed. Just by happenstance, the woman who is most willing to murder the king happens to catch the king's eye on a day when he would drink too much. He doesn't even try to sleep with her. The victory is so simple that she basically walks in, sees the sword, sees him asleep, and then executes him. The victory of the Israelites is depicted in the same imagery.
Slaughter as the image of God's goodness
One might think that God's mercy and love would be symbolized by babies and lambs and stuff, but not in this poem. In this poem, the imagery of gore and slaughter is clearly tied to the Israelites' faith in God, and his deliverance. Since the king is a horrible person and a rapist, and since the Assyrians are like him, the assassination of the king and the Israel decimation of Assyria are offered as imagery for mercy and goodness.
