There’s an original story to go with this photoset at the source, which I’ll translate/summarize here:
A fish falls in love with a man, quietly listening to the sounds of his guqin. In order to be with him, she asks the Buddha to turn her into a human. The Buddha cautions her that nothing is forever. Finally, she is able to meet the man as a person, and they spend their days in peaceful bliss.
However, one day, she discovers that the man is an immortal, who secretly defied heaven’s laws and came down to earth to be with her. She begs heaven to keep him from harm. He tells her that he chooses being with her over being an immortal. With a sigh, the Buddha muses that the immortal would throw away a thousand years of training for this one lifetime.
(So basically, a little like a Chinese version of “The Little Mermaid”.)