Babies, who hardly see much difference between such cards in the first place, will see even less differences between the combinations of letters that make up words. Such methods present children with associations that are artificial and fabricated. Natural Learning will prefer associations that children make naturally, such as in the above example of the dog. School is full of such artificial practices. At school, children are taught that house is a sequence of letters, i.e. visual symbols to be read out or written down.
School likes to concentrate on 'difficult' words, such as paralysis, perpetual and resolute.
But children have little idea what the words mean. By contrast, the example of a house is easy, as the children may still see a picture of a house with walls, windows, doors and a roof. School teaches children to spell out words, before the children even understand the meaning of the words. Then, school teaches children the equivalent of the word in other languages. Children learn how to write the word, how to translate it, how the word is spelled out in another language.