[%c_effect a3;square;a3;type;GreatFind;persistent;true] It turns out that Robson intended not only a queenside attack. This rook lift puts tremendous pressure on the black kingside, whereas the e6-pawn is once again in a delicate situation. Not everything is as one-sided as it seems though.
1. d2d4  1... d7d5  2. c2c4  2... c7c6  3. g1f3  3... g8f6  4. b1c3  4... e7e6  5. g2g3  5... d5c4  6. f1g2  6... b8d7  7. e1g1  7... b7b5  8. e2e4  8... c8b7  9. e4e5  9... f6d5  10. f3g5 One of the many aggressive attempts to gain more than positional compensation for the pawn in these lines. 10... h7h6 Mishra reacts in the most principled way. 11. g5e6  11... f7e6  12. d1h5  12... e8e7  13. c3e4 The black king is in danger, and therefore Black needs to give back a portion of the material. 13... d8e8  14. c1g5  14... h6g5  15. h5h8  15... e7d8  16. e4g5 This line has returned to the spotlight thanks to the efforts of Russian GMs Andreikin and Sarana. 16... e8e7 Galkin's approach. 17. h8h5 Robson is in turn blitzing out his moves. 17... d8c7  18. h5g6  18... a8e8 White needs open files for his rooks, and therefore the next move comes to mind. 19. a2a4 This was also practically blitzed out, and then Mishra uncorked a novelty.[#] 19... c7b8 This is practically forced. Black is not only solidifying his queenside, but also freeing up the c7-square for his knight.