Please tell me what the sentence of laughter mixed with water means. It's a love song.

Laughter and underwater sound blend together, which means playing a friendly song. It means: a vivid metaphor, which means that when laughter and underwater sound blend together, it will form a harmonious, natural and beautiful state, just like playing a wonderful music track, full of yearning and longing for love and harmony. So, please tell me, laughter mixed with underwater sound is playing a love song. This sentence is a vivid metaphor. It means that when laughter and underwater sound are mixed together, it will form a harmonious, natural and beautiful state, just like playing a wonderful music track. This state is full of yearning and longing for love and harmony. Laughter and the sound of water represent the feeling of nature and relaxation. This sentence comes from the Chinese text "Tiaotiao Song" in the second grade of primary school.