What clever metaphors did the poet use in the poem "Xi Murong's Homesickness", and what was the expression effect?

Xi Murong's Homesickness: The song of my hometown is a flute, which always rings on a moonlit night, but my hometown's face is a vague melancholy, like waves in the fog. After parting, homesickness is a tree that never grows old, using flute, moon and fog respectively. Trees without rings can describe that kind of distant, melancholy and endless homesickness. The following is an appreciation: Xi Murong summed up this homesickness with a short poem with seven lines and three sections: the first section writes that the local accent is fresh and lingering, and the flute "always rings on the moonlit night". Imagine how many nights there is no moonlight all year round, which vaguely means that travelers miss their hometown all the time. In the second part, he wrote about homesickness. Time has shaken down the outline of hometown, leaving only a vague sense of frustration, such as parting in the fog, as thick as blood, but separated by a misty cloud. Waving goodbye in the fog is a vivid and vivid description of abstract subjective feelings. The third layer describes the eternity of homesickness. This is a transition from lingering local accent and nostalgia on the upper two floors, and the form is very novel. The gradual shift of levels makes the theme clear from obscurity. The poet uses the image metaphor of a tree without wheels that will never grow old to express the deep ocean-like sadness, nostalgia and depression. The fusion of emotional expression and image choice makes the whole poem profound and far-reaching. The appropriate metaphor and concise and beautiful language make the whole poem have an idyllic artistic conception.