1. Dreaming (allegory)
Dreaming can be seen as an allegory for sin in “Echo.” After the speaker realizes in stanza 2 that a literal “Paradise” is inaccessible to her living self, she chooses to indulge in the immediate pleasure of dreams. In this way, when she describes herself knowingly accepting to be “cold in death” by dreaming, the speaker alludes to the way Christians believe that sin causes the death of the soul through the desire for immediate, but fleeting, pleasure and gratification.
Echo (motif)
The concept of an Echo is a reoccurring motif throughout the poem. Rossetti employs repetition through anaphora, repeated words, repeated phrases, and alliteration as a linguistic means of approximating the experience of a sonic echo. Elsewhere, she describes memory in a way that makes it sound like a sonic echo, namely a repetition of an experience that fades with each iteration.