Told from the point of view of a black flag hanging outside a house where someone has died, the poem turns a funeral into a quiet, slightly darkly comic scene. The flag sees everything: the red chairs waiting for the old, the mourners in black, the black umbrellas and shoes, even the men whose dyed hair they comb furtively. It feels proud of its role as "herald" of death, and a little jealous that its master gets red silk and bright flowers while it must stay black. It even claims to spot the next person who will need it.
The mood is solemn but gently ironic. The flag's self-importance and its insistence that black is "the colour of truth" are almost funny, yet the poem's blackness piles up until it feels heavy. The ending is the sharpest touch. After its long vigil in sun and rain, the flag will simply be thrown into the bin. Even death's proudest messenger is soon forgotten.