What does has it not come down to soup that was made by boiling the shadow of a pigeon that had starved to death mean?

The phrase "soup that was made by boiling the shadow of a pigeon that had starved to death" is likely metaphorical, suggesting something insubstantial or lacking in value. It evokes an image of a desperate and futile attempt to create nourishment from something that has no substance or worth. Essentially, it reflects a sense of hopelessness or the idea that one is left with nothing but an empty or meaningless outcome.