I sent thee late a rosy wreath,Not so much honouring thee As giving it a hope that there It could not withered be" (9-12)
The speaker's gift of a "rosy wreath" is odd. He doesn't send for the sake of "honouring" Celia, but rather to see if it will live forever in her presence. Weird, right? We know the speaker loves Celia, but for a split second it seems like his love is a kind of experiment: he doesn't send her a wreath as a present for her, but in order to discover if something exciting will happen.
But thou thereon didst only breathe, And sent'st it back to me (13-14)
The "but" that begins line 13 is very weird. The speaker sends Celia a wreath in order to see if it will stay alive in her presence; then he tells us "but," as if to imply that she didn't do what he wanted and only sent the wreath back to him. We realize at the end that the wreath continues to grow, but here, for a split second, the speaker's expectations appear to be frustrated.