The repeated wu syllable imitates the sound of sobbing in Chinese text and speech, where wu wu is commonly written to show crying. Clips built around that simple pattern circulate on soundboards because the meaning is clear even without words or context. Short crying reactions like this became a staple of meme edits, livestream alerts and chat stickers, letting people exaggerate disappointment for comic effect. Its appeal is its speed: five identical sobs signal the emotion immediately, so it still works in fast, silent scrolling feeds.