I tried looking at a few lines with the engine but still couldn't quite understand how white managed to obtain a better position in some of the lines. Any help would be greatly appreciated.
[Title "White to move"]
[fen "r1bqr1k1/1pp2pp1/p1n2n1p/4p3/3PP3/2PB1N1P/P2Q1PPB/R4RK1 w - - 0 15"]