Two connected pawns on the sixth supported by their king hold against a lone queen if the attacking king is far away. The queen cannot both stop a promotion and avoid losing a tempo.
A queen is worth far more than two pawns, yet here it cannot win. Black's pawns on d3 and e3 are supported by the king on e2, and White's king is on h7, too far to help. Whenever the queen attacks one pawn, the king defends it; whenever the queen pins or blocks one pawn, the other advances or the king shields it.