It's a painted portrait of words! In the movie, that scene is a confused character surrounded by strange sculpted arcs. In the book, it's a spiritual experience. There's also a section from the Silmarillon, but it's not quite as central focus for that one.
http://www.ae-lib.org.ua/texts-c/tolkien__the_silmarillion__en.htm#01In that time the Valar brought order to the seas and the lands and the mountains, and Yavanna planted at last the seeds that she had long devised. And since, when the fires were subdued or buried beneath the primeval hills, there was need of light, Aulë at the prayer of Yavanna wrought two mighty lamps for the lighting of the Middle-earth which he had built amid the encircling seas. Then Varda filled the lamps and Manwë hallowed them, and the Valar set them upon high pillars, more lofty far than are any mountains of the later days.