Black has traded off the tension and freed himself of the pin, but his pawn structure is disrupted: the queen-side pawns are isolated, and the h3 pawn will be difficult to defend. White will have to take care of his isolated d-pawn, but has no other marked weaknesses.
Avoiding the obvious d3 post. The White knight is to manoever to the king side, and White wishes to scotch any troublesome pin, for example ... Bb4 which would hinder this.
Black wastes no time bringing the White d-pawn under fire.
19. Nc3e2 Kc8b7 20. O-O-O
Indirectly bolstering the d-pawn. Once the bishop is posted to c3, the d-pawn will be solidly defended and White can then concentrate on picking up Black's far-flung h3 pawn.
20... Bf8e7 21. Bd2c3 Rh8h5
Black swings the KR onto an open rank, from which it can attack the queen-side or the king-side at will, or double on the d-file and exert more pressure on White's isolani. White must act aggressively if he is to hang onto the initiative.
Hammering e5 and removing g5 from the Black bishop's sphere of influence.
Preparing to invade the White position with, for example, ... Na4, or ... Nc4, or ... Nd5. White must defend accurately here to avoid the break-up of his king position, or a nasty knight fork.
23. Kc1c2 Nb6d5 24. Rd1d3
Holding the critical square e3 from encroachment by the Black knight.