How did the newly-opened dried tofu in Shanghai dialect come from?

In old Shanghai, there was a vendor who specialized in selling dried tofu and tea eggs. If it is not sold out that day, they will take the dried tofu out to dry and sell it the next day. So I used the metaphor of "returning soup to dried tofu" and returned to my old job.

The newly opened dried bean curd should correspond to "back soup dried bean curd".