The game does a bad job of explaining this one. But a handful of the regular challeneges have a small intro cinematic (NOT the mountain stories, those are seperate). These are the invitational challenges. I believe the list below is the full list. Get golds on these challenges, and the trophy should pop.
Red Bull - Aravis
Rooftops
Salomon Challenge
Red Bull - Big Mountain
Red Bull - Mont Blanc
Boardsleigh
GoPro Frison Roche (wingsuit)
If you're going for the trophy getting gold on all 115 challenges, then you will probably get this one in the course of that.