The idea can be slightly harder to see in a position like this where the queen is nestled back among its own pieces. Get used to spotting the significance of patterns like the alignment of Black’s rook and queen on d8 and c7 with open squares on the diagonal ahead of them. Pieces so arranged invite an attack by a bishop, as with Bb6—this time taking protection from the White knight on a4 and again winning the exchange after Black moves his queen to safety.