Echo says that the beauties we enjoy or possess don't actually belong to us. Huh?
The line is puzzling, to say the least. To whom do the beauties belong then? God? Nature? Our next-door neighbor? Brad Pitt? There's just no knowing for sure.
Still, let's remember that Echo is lamenting the death of her man, Narcissus. So "beauties" might refer to him, the boy that Echo loved, but who, at the time of poem, is dead. He was her beauty, but now he isn't anymore.
If that's the case, we might read this line as saying, "our beauties, or the things we find beautiful, aren't ours because they are eventually taken away by death. "
Jonson hasn't finished with his rhyming yet either. If we add this line onto the scheme we've built already, then the poem goes a little something like this: ABABCCC.
Oh, I could still, Like melting snow upon some craggy hill, Drop, drop, drop, drop, Since nature's pride is, now, a withered daffodil.
Echo again comments on how sad she is; she says she could "drop, drop, drop, drop" like "melting snow." The reason Echo says she could drop is that "nature's pride" is now a "withered daffodil."
If there were any doubt as to what Echo is talking about, these lines seal the deal. The daffodil? That's totally Narcissus. He was "nature's pride" because he was really ridiculously good looking. (For more on what we're talking about, check out "In a Nutshell.")
These lines give us an image of perpetually falling. It's as if Echo will never stop mourning, she'll just keep drop-drop-dropping. "Drop" means drip or fall down, but here it could also mean to drop dead, so to speak.
By comparing herself to melting snow in a simile, Echo shows us just how slow a process grief is. She can only mourn for her Narcissus drip by awful drip.
Just to end on a high note, Jonson gives us another dose of rhyme with these last four lines. Added to the rest of the poem, they complete the pattern: ABABCCCDDED. That's a jaunty pattern for such a sad, sad song.