Don't overanalyze the article. Draw a supply and demand model for Costco rotisserie chicken. Make sure to label everything in the model. Label the initial set of supply and demand curves as 2010 curves - label the initial equilibrium quantity as the 2010 quantity from part c. Label the initial price as $5. Then move either the demand or the supply curve (not both) based on information from the article. Label it as a 2017 curve. Label the final price as $7 and the final equilibrium quantity as the 2017 quantity from part c (even though it is just from Costco).

https://www.wsj.com/articles/rotisserie-chickens-the-nineties-gift-to-supermarkets-that-keeps-on-giving-1515061801