Final answer:
Aunt Julia's singing of "Arrayed for the Bridal" symbolizes situational irony, as she is likely dressing for a funeral, contrasting with the wedding implications of the song.
Step-by-step explanation:
The ironic symbolism behind Aunt Julia singing, "Arrayed for the Bridal" reflects the contradiction between the song's title and the actual situation. Rather than preparing for a joyful wedding celebration as the song might suggest, Aunt Julia is dressing for an event that is sorrowful, most likely a funeral, as implied by the references to mourning figures and a funeral bier in the provided context. This stark contrast between the song and the scenario exemplifies situational irony, where what is expected is vastly different from what actually occurs.