comment: The point of ​​this move is to restrict the development of the c8-bishop. The main ideas of White's setup are using the outpost on e5 and keeping this bishop trapped behind the pawn chain.
context: 1. e2e4  1... c7c6  2. d2d4  2... d7d5  3. e4d5  3... c6d5  4. f1d3 Carlsen has played this system many times, with both White and Black. 4... g8f6 