Arrasou is Brazilian Portuguese slang for nailing something or looking amazing, and bonita adds a direct, affectionate compliment, so the two words together work as instant praise. The phrase is common in everyday Brazilian speech and in online comments, where friends use it to hype each other after photos, videos, and performances. As a short sound, it fits the fast style of reaction clips and memes, because listeners understand the tone even without translating every word. That mix of warmth, humour, and confidence keeps it useful for celebratory edits.