Do not weep, maiden, for war is kind, Because your lover threw wild hands toward the sky And the affrighted steed ran on alone, (1-3)
The maiden's lover is killed in battle. The image of man and wife, boyfriend and girlfriend comes to mind. One of the two pillars of the household is killed, which leaves the home a broken and incomplete place.
Do not weep, babe, for war is kind. Because your father tumbles in the yellow trenches, Raged at his breast, gulped and died, (12-14)
The way in which the speaker goes right from addressing the babe, who is presumably in a cradle in a home somewhere, to the battlefield implies that the home is as much a part of a war as the battlefield itself. The speaker makes the same move in the first stanza as well.
Mother whose heart hung humble as a button On the bright splendid shroud of your son, (23-24)
The image of a mother doting on her child is a very homey scene. But here, that scene is evoked and perverted as the mother is hanging over her son, but he's dead. Yikes.