"they hadn't been staring at my watch. they had been staring at my food". discuss the significance of this statement and how it changes amir in some small way. chapter 19

One of Wahid's wives brought dinner to Amir and Farid, saying the family had eaten earlier. As he ate, Amir noticed that Wahid's three boys were staring at his watch. After asking for Wahid's permission, he gave it to them. To his surprise, it did not impress them very much. From inside, Amir heard one of Wahid's wives scolding him for not leaving any food for the children; Amir realized that the boys had been staring not at his watch, but at his food. Before he and Farid left the next morning, Amir tucked a wad of money under a mattress for them to find.