The fact that the slope of the production possibilities curve becomes steeper as we move down along the curve indicates that:

The fact that the slope of the production possibilities curve becomes steeper as we move down along the curve indicates that the principle of increasing opportunity cost is relevant. It follows this law as the number of production is increased, the product also increases above the usual amount. An example is when your business such as pastries has good marketing and sales and you want to increase your sales by increasing your area, adding machines and all.