Slow, slow, fresh fount, keep time with my salt tearsYet slower yet, oh faintly gentle springs (1-2)
The emphasis on slowness suggests a gradual slowing down of life, as if Echo is withering, just like her daffodil boyfriend. It's as if Echo wants the springs to gradually stop singing, moving, or whatever it is that they are doing. Does this remind you of anything? Aging, too, is a gradual slowing down, and it's something most of us have to go through, unless we have the distinct misfortune of dying young, like Narcissus.
Droop herbs and flowers;Fall grief in showers (5-6)
Once you've read the whole poem, it's hard not to notice how the words "droop" and "fall" foreshadow the word "drop" in line 10. In a way, these words also suggest death. When we see flowers drooping, for example, it usually means they are almost dead, or in the process of dying. Echo sees death all around her, either because it is all around her, or because she's so sad it seems like it is.
Oh, I could still (8)
What a line break. Ending on the word "still" makes us think of the stillness of death, especially considering the context of the poem. It's as if the sentence just dies right there at the end of the line. We pause, for a minute, and experience a sense of stillness as we ponder what might come next.