Fantastisk is the Scandinavian word for fantastic, used across Norwegian, Danish and Swedish, and du e fantastisk is a dialectal way of saying you are fantastic in Norwegian. No specific film, song or show is confirmed as the source for this short clip, so its life online comes from the phrase itself rather than a famous scene. Short compliment sounds like this circulate on soundboards because they are easy to reuse as praise, encouragement or gentle teasing, and this one stays popular for its warm tone and instantly clear meaning.