Why are illustrations (object lessons) at the beginning of each lesson?

The illustration is designed to give the children an easy-to-understand, concrete example to direct their thinking toward the lesson theme. Material is presented in a deductive teaching style, leading children to make observations and draw conclusions as the lesson progresses. Therefore the illustration is an important bridge from what children see and understand (concrete thinking) to what they can't see and find hard to understand (abstract thinking). Children learn through the process of bridging this intellectual gap.