There are various ways of thinking about what is beautiful in poems.
It's possible that in our present climate we fail to recognize the role of understatement, evocation.
A self-effacing description evokes a scene, creates atmosphere.
(The kind of sensorium we sometimes associate with autumn.)
Words that fade into an imaginative impression : say an experience in which a setting - a particular place or time - seems to combine with a state of feeling, or with a particular situation, or state of mind.
Words perhaps share with music (to a degree, anyway) a certain capacity to vanish behind (or dissolve before) the state of mind they evoke.
Something elusive about this. There may be a name for it...