For complete happiness White needs to play both h2-h3 and  0-0. But with the arbiter around he has can chose only one of the two...
1. d2d4  1... g8f6  2. c2c4  2... e7e6  3. b1c3  3... f8b4  4. e2e3  4... e8g8  5. g1f3  5... c7c5  6. f1d3  6... c5d4  7. e3d4  7... d7d5  8. c4d5 Now Aronian slightly surprised his opponent with a pawn capture: