Some eagle eyed-viewers may have noticed a QR code in Rocket Mortgage’s Super Bowl spot. Midway through the commercial, which uses Anna Kendrick and Barbie to advertise Rocket Homes, one of the children is shown sporting a t-shirt with a QR code. The code is for StockX, the resale platform co-founded by Dan Gilbert, who is also founder and chairman of Detroit-based Rocket Mortgage.

The code leads to a StockX website that reads, “Well look who it is. Congrats on seeing our cameo in the Rocket Homes and Rocket Mortgage big game commercial. Now you have access to enter an exclusive ReStockX.”

The site allows users to bid $1 on its Big Game ReStockX page where they are entered to win prizes such as Beats x Psychoworld Studio 3 headphones and Blue Toe Union Jordan 1 Highs sneakers, currently available for near $2,000 on StockX.

Casey Hurbis, chief marketing officer at Rocket, advised Ad Age earlier this month to be on the lookout for Easter eggs in the brand’s Super Bowl spot.

“There are opportunities to have additional surprises,” he said. “We with the Super Bowl love to have Easter eggs and surprises along the way.” He said he expected a lot of conversation around Anna Kendrick and Barbie, but warned, “Make no mistake, there are other unexpected moments in the campaign and spot.”

This isn’t the first time the brands have collaborated, Hurbis said on Sunday. "A character in our 2018 Rocket Mortgage Super Bowl commercial wore a StockX hat. The Super Bowl ad gave us an opportunity to help shine a spotlight on another Detroit-based tech brand, and we took it."

A Rocket spokesman confirmed Sunday the StockX code was one of the “fun” eggs to which Hurbis had alluded.

A StockX spokeswoman did not immediately return a request for comment. Mojo Supermarket, which is the brand’s lead agency, was not involved in the cameo. The brand has been moving beyond its sneaker origins into other categories of collections.

StockX teased the cameo on Twitter earlier today.

After Rocket’s commercial, which was created with Highdive, ran in the second quarter, many on Twitter wondered about the code.