Olga feels pity for Lushkoff. She knows that such a weak man cannot chop wood. So, she helps him by chopping the wood for him. Even though Olga's words are harsh, deep down, she has a kind and helpful nature.
This act of kindness from Olga changes Lushkoff’s heart. If Olga had not helped him with the wood, Lushkoff wouldn't have earned the money he needed. He also wouldn’t have had the chance to hear Olga’s moral lessons.