My question is specifically regarding black's moves: 13...Bf5 - 14...Be6.
I can understand the reason for move 14...Be6, as it provides cover for the king after white's rook attack. But, why not move there on move 13?
Instead, the computer shows that black should move Bf5 on move 13, only to move back to Be6 after the discovered attack from white.
Why?
Black to move
