Projection is one reason why the tarot cards are valuable. Their intriguing pictures and patterns are effective in tapping the unconscious. This is the personal aspect of the tarot, but the cards also have a collective component. As humans, we all have certain common needs and experiences. The images on the tarot cards capture these universal moments and draw them out consistently.
People tend to react to the cards in similar ways because they represent archetypes.
Over many centuries, the tarot has evolved into a collection of the most basic patterns of human thought and emotion. Consider the Empress. She stands for the Mother Principle - life in all its abundance. Notice how her image conjures up feelings of luxuriance. She is seated on soft, lush pillows, and her robe flows in folds around her.