The phrase builds on modern slang where slay means to look great or succeed with confidence, paired with an excited oh my god reaction. Short voice clips like this spread on TikTok, Reels and soundboards because they work without context and can be dropped over almost any reveal. The drawn-out slayyyyy spelling in the original title mirrors how the word is stretched in the audio. It stays popular as a quick, positive reaction that signals approval faster than a comment or caption could.