Good guides do not just demonstrate and step back. They pull the learner into the actual task and hand over more of it as the learner becomes able. Along the way they give spoken and unspoken cues, as when mothers teach weaving by letting the child do more and more of the real work.
More skilled partners help a learner connect what they already understand to what they don't yet grasp. They also arrange the situation so the task is within reach. This framing lets a beginner take part in work they could not manage alone.
Children learn to think and reason by taking part in the real mental work of their community alongside more skilled partners, not by absorbing lessons alone. Parents, other adults, and older children share the task with them. The child's thinking develops inside that shared work.