It means to describe the scene of willow trees in shade and flowers in full bloom in spring, and it also means difficulties and turning points.
This idiom comes from Wang Wei's Early Morning. Most of Wang Wei's poems are landscape works and pastoral works. At the same time, they depict natural beauty and show some carefree little interests in leisurely life. In Wang Wei's poetry creation, five laws and five sentences are often used, with delicate language and slow syllables. These writing characteristics are usually used to express the poet's leisurely mood. In the past, many people praised Wang Wei's landscape poems, on the one hand, because of his superb artistic skills, on the other hand, because of the leisure and negative thoughts contained in them, which caused a lot of criticism.