patzerboy: From move 24 on White could have taken the Black b-pawn at any time, but he never does as there is always a better alternative available: 25. f4 consolidates the kingside. No hurry. The b-pawn can't escape. (White is thinking.)
26. Let's attack the rook on b7. Still no hurry. Black can't take the my b-pawn, obviously.
27. b6. Sure, a supported, passed rook pawn would be nice. Let's exchange queens, by all means!
28. Rf7. Uh, no. 27...g5 does not help you, and this is why.
29. Rxc7. Now what are you going to do with that bishop?
30. Qb7. I still want to know what you are going to do with that bishop, and I guess you noticed that your pawn on f7 is also in trouble.
31. Rd7. Oh, look. I get the bishop after all!