Neutral Tones

I (and others) find "Neutral Tones" to be the bitterest poem in the English language. Focus in your response to this mainly on the speaker's tone and on how it is reflected in the imagery.
--
At first I thought the term was bittersweet, but no, bitter is fitting with this poem. The speaker is one of a pair, likely lovers considering the final stanza. The speaker is recalling this scene, this lover, though he admits that other happenings have colored the memories since these events.

"Since then, keen lessons that love deceives,
And wrings with wrong, have shaped me
Your face, and the God-curst sun, and a tree,
And a pond edged with grayish leaves."

The poem is set in winter, which can be beautiful, but is not described as such here. Where the sun could have been white like fresh snow or something pleasant, it’s instead “white, as though chidden of God” the grass if “starving sod” the leaves were “from an ash, and gray” which I feel was just to heighten the drabness of this scene. It’s richly drab if that’s anything. Even the way his lover looks at him. “Your eyes on me were as eyes that rove//Over tedious riddles of years ago” Where she is obviously studying him, he gives the image age and a sort of boredom or tedious nature. One would eventually get bored of studying ancient riddles or at least tire of it. Even her smile and grin were remembered foully. Her smile was “the deadest thing//Alive enough to have strength to die” then her grin was “a grin of bitterness thereby//Like an ominous bird a-wing.” One wonders if this was a foul and dark memory before the pair obviously turned out poorly with hatred at least from his side.