The process of making a Super Bowl ad often entails the deployment whiz-bang special effects honed with weeks of editing and fine-tuning. Not so for Diet Coke, which this year converted what was originally supposed to be a quick social media video into its 30-second in-game TV ad.

The spot, by Anomaly Los Angeles, shows actress Hayley Magnus extolling the virtues of Diet Coke's new Twisted Mango flavor with a little dance. The video was originally meant to be part of a portfolio of tweetable videos for the brand's new "Because I can" campaign that touts Diet Coke's new flavor lineup that comes in slim cans.

Magnus improvised the scene while filming in intense heat in east Los Angeles, says Danielle Henry, group director of integrated marketing content for Coca-Cola North America. It was filmed in one take and directed by Paul Feig, whose credits include the "Ghostbusters" reboot and creating the TV series "Freaks and Geeks."

The brand liked the video so much that it became its Super Bowl ad. The spot marks the first time Diet Coke has run an ad in the game since 1997.

"This little teeny tiny snackable peice of social content ended up being one of the best pieces of content that we have in the campaign because it's one of the things that best showcases the attitude of Diet Coke's 'because I can'—-that being do whatever makes you happy no matter what anyone else thinks," Henry says.

Magnus is among a larger cast of up-and-coming actors that Diet Coke put in the broader campaign, which debuted in late January. The approach contrasts with the brand's prior strategy of plucking big-name celebrities and pop stars, like Taylor Swift. Magnus herself plays the character Simone on the Australian TV series "Wrong Girl."