Using these meditations with children is not the same as reading stories to them. Reading is passive. Children do understand and become involved in what you are reading, but in guided meditation they become actively involved.
Reading a story and reading a meditation are different functions. Reading stories to children is a must because it helps the child to learn and spell, but meditation enables the mind to become free, to explore.
Each meditation has its own distinctive theme and gives children the opportunity to experience it. They feel the love of the Buddha; radiate loving-kindness; climb mountains; collect seashells; become a bird; feel the touch of the wind on their face; and go to the moon.
There are so many things they can do, and all these things must bring their imagination to the fore. Most importantly, they learn to appreciate the Dharma more. In other words, they participate in the meditation and learn to be in touch with the source of love, strength and wisdom inside themselves.