What does it mean that tofu pudding floats in Zi Yuan?

This is a epigraph name, and the floating element of tofu pudding refers to the phrase "green new Zen" in Bai Juyi's "A suggestion for my friend Liu".

The meaning is simple. In the Tang Dynasty, a young man named Zhang Ji (named Wenchang) and his friends went to the suburbs to play, and saw a large shade with lush weeping willows and yellow cicadas chirping on the trees. The first two sentences of this poem describe the scenery and point out the seasonal environment.