"Seeing"

This term we have read a lot of transcendental nature writing, so my first question on my 11th grade final asked students to read the following passage from Annie Dillard's essay "Seeing," and explain the metaphor of the "tree with the lights in it." I have gotten such a WIDE range of responses I would like to see what you think.

“When her doctor took her bandages off and led her into the garden, the girl who was no longer blind saw ‘the tree with the lights in it.’ It was for this tree I searched through the peach orchard of summer, in the forest of fall and down winter and spring for years. Then one day I was walking along Tinker Creek thinking of nothing at all and I saw the tree with the lights in it. I saw the backyard cedar where the mourning doves roost charged and transfigured, each cell buzzing with flame. I stood on the grass with the lights in it, grass that was wholly fire, utterly focused and utterly dreamed. It was less like seeing than like being for the first time seen, knocked breathless by a powerful glance. The flood of fire abated, but I’m still spending the power. Gradually the lights went out in the cedar, the colors died, the cells unflamed and disappeared. I was still ringing. I had been my whole life a bell, and never knew it until that moment I was lifted and struck. I have since only very rarely seen the tree with the lights in it. The vision comes and goes, mostly goes, but I live for it, for the moment when the mountains open and a new light roars in spate through the crack, and the mountains slam.”

1. What on earth is she talking about?

Don't worry, I won't mark you down for a wrong answer :)