The speaker is alone in a room that still holds traces of someone who is gone. His cologne hangs in the air, his suit cuffs sit in a drawer, and opening that drawer brings tears. Even the walls seem to murmur in his hoarse voice. Nothing here is dramatic, and that is what makes the grief feel so real: it lives in small, ordinary objects.
The turning point is the diary. The speaker finds that the loved one wrote about her in every way, and the dried roses that fall from its pages feel like pressed memories crumbling. The last lines hold the poem's central idea. She loved a writer who made her "immortal" on the page, but only by wasting away himself. His death is the price of her permanence.
The mood is quiet, tender and aching. There is sorrow, but also a bittersweet pride that she has been preserved in his words.