At least four important devices appear, and they do not all work in the same way. Recognizing their differences reveals how the passage is constructed.
ExampleDeviceEffect
White/red bannersColour imagery and exaggerationIntensity of battle
Our mill / flourExtended metaphorWarfare as grinding
Guests / hospitalityIrony or mock courtesyHostile reversal of hospitality
Kaʾanna + skull imageryExplicit simileDramatic scene of falling
Context is decisive. The ordinary meaning of “guest” cannot determine the sense when the supposed hospitality consists of a crushing stone.