The tone of "I am Like a Rose" by D.H. Lawrence is pretty hard to miss, it seems to me. Here the speaker of the poem is comparing himself to a rose--and the rose suffers by comparison. In literature, the rose is a traditional symbol of perfection, purity, beauty, and love. In life, giving roses expresses one's love. With that in mind, making the comparison between one's self and a rose is pretty ambitious; if someone implies they are better than a rose, we'd probably see them as arrogant. That's the tone, I think, of this poem. Arrogance and superiority.
The speaker (presumably Lawrence himself) in the first stanza says he has achieved his "very self," and, like a single perfect rose, has "issue[d] forth in clear/ And single me, perfected from my fellow." He is, it seems, much more perfect than the rest of mankind--the rest of us. He is separated from the rest of the more typical, ordinary roses by his perfection--a reality which creates "wonder mellow" and a "fine warmth." In the second stanza the self-congratulatory tone continues:
Here I am all myself. No rose-bush heaving
Its limpid sap to culmination has brought
Itself more sheer and naked out of the green
In stark-clear roses, than I to myself am brought.
The finest rosebush, he claims, has never--despite its best efforts--produced a rose as perfect as he. The tone is clearly one of superiority and arrogance. He has finally arrived at perfection, it seems ("I am myself at last")--a perfection which clearly outshines everyone around him.
I agree Lawrence himself is talking. He is comparing himself to this beautiful flower. He feels as if he has arrived at some point in time. He has opened his self up so everyone can see. Showing everyone his imperfections. And it feels great. He is free. ( No rose-bush heaving) There is nothing holdining him back. Nothing to hide.