Why is this exact position good for black?

Why is this exact position (after 26. Ra7) good for black?
I don't understand what is it that makes it a good position for black?
Can anyone please explain and help?

@Dragon-Emperor The position is unclear, with mutual chances. You have to play the strength of Sookfish to understand this position.

Black is a pawn up and has a good knight on e4, while white's knights don't have a lot of good squares after 26... f6. Plus the e5 pawn could be hard to stop in the future. That's what I see :D

I mean, a pawn up, 3 pawn islands vs. 2 is bad news for White.

The d7 knight is some what trapped you are already up a pawn f5 f4 establishes a pin on the knight after Be3 moves the Ra7 rook is stuck defending the knight for the moment in fact Nc3 wins another pawn so it looks good for black.