A disgusting viral video of KFC workers repackaging old food shows why a recent strategy has been vital to the chain's survival (YUM)

And it reveals something important about the chain.

In the video, workers take green beans and mac and cheese out of cartons and plop them into containers to be served to customers the next day. Chicken that had been left out since the afternoon was also packed up to be served the next day, after nearly 24 hours sitting out.

"Look at these old green beans," a worker says. "These green beans have been there three to four days."

While the video paints a grim picture of KFC, a representative for the chain told Business Insider it was an "isolated restaurant and it does not accurately represent our company food-handling procedures, policies, or values."

But the video does highlight some major changes the company has made over the past few years to improve its reputation.

In 2013, when the video was filmed, the chicken chain was in a dark place.

"In the birthplace of this brand, KFC hasn't done well in decades," KFC's chief marketing officer Kevin Hochman, who has since been promoted to president, told Business Insider in 2016. From 2002 to 2016, KFC went from 5,472 locations in the US to 4,270.

In April 2016, KFC launched a "Re-Colonelization" program, which included a national employee retraining and a new satisfaction guarantee. Executives said customers had complained that food "didn't taste the same," and many Americans simply didn't trust the chain's quality.

"You can't just pivot from Double Downs to 'We make fried chicken in the back of the house' overnight," Hochman said at the time.

"While Re-Colonelization was not related to this incident, it included investing more than 100,000 hours in team-member training and recertification of our cooks, going back to the Colonel's values on how we prepare and serve food to our guests, and most importantly, inviting America back into our restaurants for a new experience," a KFC representative told Business Insider.

The Re-Colonization employee training, coupled with a successful Colonel Sanders-centric ad campaign, has paid off for KFC.

In August, the parent company Yum reported that same-store sales increased 3% in the most recent quarter, with CEO Greg Creed calling the brand a "global powerhouse" achieving things "no one would have believed possible three years ago."

So, the viral KFC video is an important one for the chain. But its importance came not because it dissuaded customers from eating at a disgusting restaurant but because it showed how much the chain needed to improve — and how KFC reacted.