What changes have been made in the emotional tone of the poem "Seeing Shen Zifu to the East of the River", which is similar to the author's metaphor of lovesickness with spring scenery?

It shows that the poet sent his good friend away, and suddenly there was only one poet left on the originally quiet ferry. The poet looked at the spring scenery again and felt lonely in his heart. ...

The last two sentences mean: let my thoughts in my heart remind me of the ubiquitous spring scenery. From Jiangnan Jiangbei, I will pounce on you and follow you.

The metaphor of lovesickness with spring scenery is that the poet entrusts his thoughts to various spring scenery in the southeast and northwest, and rushes to that friend together.