The phrase is Brazilian Portuguese internet slang, with Nossa acting as an exclamation of surprise and mítico used to describe something legendary or exceptionally impressive. Essa passagem points to a particular passage, play or sequence, which is why the clip fits gaming highlights, football moments and other short videos where one sequence deserves special praise. Shared as a compact reaction sound, it has circulated among Portuguese-speaking creators who want a fast, recognisable way to mark a standout moment without explaining it, and its short length makes it easy to drop into edits, memes and reaction compilations.