From a static point of view, this sentence describes that "the plain posture is good at hiding fragrance", which refers to plum blossoms, and the plain posture is plum blossoms dotted with snowflakes;
From a dynamic point of view, duality describes "falling trend is also oblique to dancing trend", falling trend describes falling snow in succession, dancing trend can refer to plum blossom swaying in the wind, and from a dual point of view, it should describe the latter situation. If you want to translate it, it is probably that the snow dances with the plum blossom in the wind, and the snow falls (obliquely) where the plum blossom swings.
But personally, I think this translation is more painful. The purpose of the author's "writing landscape" is to "create environment", and it is important to make the reader have a spiritual soundness without word-for-word translation.