Explain the extended metaphor in Jonson's "Song: To Celia."

Song: To Celia - Parallel Text

Simply drink to me with your eyes,

And I will promise faithfulness with mine.

Or put nothing in the cup but a kiss,

And I'll not wish there was wine in it.

The thirst felt by the soul

Longs for a divine drink.

But even if I could sip from the immortal drink of the gods,

I would not exchange it for yours.

Lately, I sent you a wreath of roses--

Not so much to honor you

As in the hope

That it would never wither.

You merely breathed on it

And sent it back to me.

Since then it keeps growing--and I swear that it smells

Not like flowers, but like you.