Kelliya isn't named until the very last line, and that delay is the whole trick. For thirteen lines the speaker piles up images of wonder: falling stars, petals raining down, a sky that seems to sing. Only at the end do we learn what set it all off. It's the feeling of simply thinking of one person.
The images are big, bright and a little dreamlike. The "clouds of invisible birds" are a lovely oddity, since we can't see them, but we can almost hear them. The petals fall "like raindrops or teardrops," which hints that the joy may be tender enough to be close to tears. Then the world's troubles, "every societal ill," melt into colorful shapes, like a kaleidoscope bursting apart. The speaker suggests that this person makes everything else feel smaller and softer. The mood is joyful, giddy and overwhelmed, the sound of someone too happy to describe it plainly.