We saw a similar maneuver in the now famous match game between Ding Liren and Nepomniachtchi. I must admit that I already had difficulty understanding the move in that game and I have even more difficulty understanding it in this one. In fact, I must admit that Arjun's moves in general are incomprehensible to me—perhaps that's why he is my favorite chess player nowadays.
1. d2d4  1... g8f6  2. c2c4  2... e7e6  3. b1c3  3... f8b4  4. f2f3 An extremely dynamic, creative and risky opening system, matching Arjun's playing style. 4... c7c5  5. a2a3  5... b4c3  6. b2c3  6... b8c6  7. e2e4  7... d7d6 A typical Nimzo-Indian pawn structure. I've always liked Black in this type of position. 8. g1e2  8... h7h6 This move prevents the pin with Bg5, but for me it's not clear that it's necessary. Black could castle or immediately begin his traditional plan on the queenside with b6-Ba6.