The economic impact of a holiday fad is illustrated by what?

As the context states, events and supplies can generate changes in the demand curve. A holiday fad is one such event that dramatically increases demand for a short time. This is illustrated in the holiday of Christmas. As Thanksgiving and Black Friday ends, demand for goods drops for a short time. But once Christmas approaches, demand for toys, clothing, and even cars increases as citizens seek to purchase gifts for loved ones. This is increased by the implementation of sales and deals that can help move products and make money for companies as an excess volume of goods are purchased.

So, to answer the question, the economic impact of a holiday fad is illustrated by the market demand curve shifting rapidly to the right.