The speaker jots a rose and a wren into a memorandum book, the kind of notebook where you'd normally keep errands and reminders. Already there's a gentle joke in that: a flower and a small bird are filed away like business items. The title, "Thought leaders," adds to the irony, since the poem's real authorities seem to be these humble, living things rather than anyone grand.
In the second stanza, the speaker puts them under "wonderful but plain," a phrase that sums up the poem's attitude. The rose and wren aren't flashy, but they have "a different kind of presence." The last stanza turns toward people, or perhaps the speaker and the reader: "alone together," promising "to speak with our hands." That could mean gesture, touch, or simply making and doing rather than talking. The mood is quiet, warm, and modest, with a sense that attention matters more than noise.