Rose as symbol of short-lived beauty
The rose is not a flower that blooms for a long time. But its fragrance and fallen petals remain, reminding everybody how beautiful it used to be when it was alive. Wilmot, who died at age 33 and who possessed good looks, charm, and unique literary talent, is being compared to the rose.
Light as symbol of insight
Wilmot's death is compared to the quick departure of light, and his genius is depicted as light that, like the Sun itself, could not be hidden.
Arrow as symbol of love
Cupid's arrow, when shot into a victim, causes that person to fall in love. The broken arrows piled around "Strephon's" monument represent love that will not come into existence, now that the person who inspired so much of it is gone.
Flowers as symbols of female romantic interest
In the Italian, Portuguese, and Spanish languages, the word "flower" is sometimes a euphemism for part of a woman's anatomy. But the garlands of flowers brought by the "Beauties" to grace the tomb are watered with their tears. The Cupid characters in the following stanza were instructed to bring not flowers but their broken arrows. (Freud wouldn't be born for many, many years, but it's OK to interpret things in that context. With Rochester and his clique, if you think something might be a sexual reference, you're almost always right.)
"Stygian gods" as symbol of death
In the classical Greek tradition, the river Styx separated the world from the underworld. Everyone who died had to cross the river. On the other side, Hades -- the god of the underworld -- and his wife Persephone awaited, along with the shades of everyone else who had died. Unlike the mythical Orpheus, who so charmed Hades that Hades allowed him to venture into the underworld to rescue his dead wife Eurydice, Aphra Behn will not be able to write Rochester back to life again. He must therefore be immortalized in some other way.
