I would say that the tone of this second stanza is one of disappointment and longing.
In this stanza, the speaker has sent his love a wreath of flowers. He hopes that it will stay on her and remain beautiful there. He is sending it as a token of love and of praise for her beauty. But she does not even hardly pay any attention to it and sends it right back.
Now, the speaker feels sad and he wishes things were different. When he smells the flowers, he smells her more. This symbolizes how much he is longing for her -- he feels her presence in the roses that she rejected and sent back to him.
The tone of the second stanza is particularly important. A strong case may be made that the speaker is demonstrating his ingenuity rather than simply complimenting his lady. He succeeds in complimenting her breath (stating that it is comparable to that of the rose), but he also qualifies his reasons for sending the wreath (line 10). It is clear that he wishes to draw attention to his own wit, but also to cause the lady to observe that he is persistent in his attention. The tone can be considered unintentionally ironic. This is a great poem to study as it relates to how we speak as individuals, and do we really hear ourselves talk? If we do, we would always put the listener first, but sometimes, it is forgotten, and we end up talking more about ourselves than the people we are speaking with.