This is the preface written by Mr. Hu Shi for this poem.
The "firefly" in the poem, as a physical image, can be regarded as a "firefly" on the water, and it is its reflection in the water, not necessarily a firefly. There are many kinds of fireflies, which may also be emitted by aquatic organisms. This is a little poem influenced by imagism. Some scholar Sun pointed out that Hu Shi's famous poem "On the Lake" was written in the concrete way of imagism. In fact, everyone can make his own interpretation of his image according to his likes and dislikes and life experiences. Personally, I think fireflies here refer to a pair of lovers who have been tested and finally joined together until they die.