What are the artistic features described in the first two sentences of Yugan Hotel's poem?

The first couplet of this poem depicts a picture of west wind and fallen leaves. The poet stood alone outside the hostel and stared. The whole world was clear and spacious because of the shaking of the vegetation. The faint twilight has spread to the end of the day. The green maple, which was originally dense, has now become sparse and is about to wither. This description of autumn scenery not only implies the passage of time and festivals, but also sets off the sadness of the poet's feelings and reveals a melancholy homesickness.

At the beginning of dusk, the sparse maple forest (falling frost leaves) touched the poet's homesickness; //As the twilight grows, the lonely city closes, the lonely bird returns to its nest, and the poet's loneliness becomes deeper and deeper; //As night falls, the moon rises, and the empty ferry makes the poet homesick: at this time, I don't know where the anvil slams the cold clothes, and the poet's homesickness is even stronger. //With the help of this series of homesick images, poems are constantly superimposed with the progress of time, thus gradually enriching homesickness.