Characteristics of US Economy
Supply is represented by this image because there are products produced for customers to buy, in this case Diet Coke.
Demand is represented by the long line of people waiting for something. They all want something and the line shows that they are willing to wait in line to get it.
The single tree represents scarcity because it is the only tree for a long distance. If shelter or food was wanted by animals then they would have to compete for these limited resources.