Put the meaning into your own words.

The example describes a present-biased choice between a small reward now and a larger reward later.

Choosing between supplies available now and a larger set later made the theater's planning intertemporal. Months ahead, the team preferred six bulbs a month after pickup day to four on pickup day; when that day arrived, it suddenly chose four immediately despite unchanged needs. The treasurer called that reversal present-biased because the immediate option gained disproportionate weight.