A poem should be implicitly aware that reality is not canny. It is background-irradiated with a mystery as terrible and as beautiful and as sad as a De Quincey laudanum dream.
That's why Tomas Tranströmer is special. He doesn't have to write about the Uncanny, but he's aesthetically refined and sensitive enough that it is a conditioning factor. It's in the voice, or behind the voice. True artistry.
Writing on the surface of things, so to speak, is merely a fine blathering and a rather dull business. That's all I have to say, and it doesn't matter anyway.