It's a string of kanji, each of which has a meaning, but which don't convey a connected meaning when read together:
音 sound
羽 feather, wing
葉 leaf
水 water
白 white, plain
碧 blue-green
鳥 bird
山 mountain
世 world
空 sky, empty
靜 silent
色 color
果 fruit, result, end
文 writing, pattern
There are a couple of posts about it on 2channel. One says it kind of describes the progress of this episode.
Another puts the kanji together into 2-syllable expressions:
空・音 sky-sound (sora oto)
世・果 world-end
鳥・羽 bird-feather
山・水 mountain-water (means "landscape")
碧・葉 green-leaves
色・白 color-white
静・文 silent-writing
Another post reassembles them into a sort of Japanese poem like this:
水碧くして葉の色山を文す
鳥の羽音静かにして
世の果て空ただ白し
"The water-green colored leaves pattern the mountain.
The sound of birds' wings become silent.
The sky at the end of the world is white."
I expect there are other ways of reassembling the kanji that will give other impressions.