Black has many development options: he can put the bishop on g4, play 3...e6 and then develop it with the fianchetto (b6-Bb7) or he can immediately develop the other bishop with 3...g6. The move played is also natural and good.
1. g1f3 Historically Ding’s main move is 1.d4. In his first white game he went for 1.e4. Now he tries a third option. 1... d7d5  2. e2e3  2... g8f6  3. b2b3 Ding has never played this before. With this move he shows that he wants a position without much theory and without many risks for this game.