The first symbolism, which is the store, symbolises Tommy's inprisonment and his horrible life, also that he did not choose the type of life that he has. "Tommy would marry her and the father-in-law would, out of his savings".
The second is the little girl that represented the past of Tommy and the bad things that he used to do. He saw a little of himself in her and he knew what she was going through. "He found himself thinking about the way his life had turned out, and then about this girl, moved that she was so young and a dief.
Finally, the tissue paper symbolises a distraction because in that way she could steal the chocolate bar. When Tommy went to the back to get the tissues, the little girl take advantage and steal the chocolates. "he had noticed, when he went to get the paper, that she steal the chocolates".
In my opinion this story teaches children that they do not have to steal nothing from anywhere.
