Black has hopes of setting up a "fortress" on e6 so the White king can't cross over to the kingside and the queen won't be able to do anything by herself because the pawn can't advance to g6 without being taken. Unfortunately for Black, that plan doesn't work.
This position arose in Pismenny-Shwartz, Moscow, 1968: 1.g5 Re6 2.Qf6 What a brilliant move! Black can't take the queen because it leads to a lost king and pawn ending and Black's choice of squares is now more limited and leads to mate. 2...Kf8 3.Kd8 Kg8 4.Kd7 Kf8 4...Rxf6 5.gxf6 Kh7 6.Ke8 Kg6 7.Ke7 Kh7 8.Kxf7 5.Qh8#