During Monday night's red flag at the Daytona 500, FOX's TV cameras showed the drivers chatting with one another and looking at Brad Keselowski's phone after the driver had tweeted from inside the car.
At one point, viewers saw an shot of Dale Earnhardt Jr. seeming to chuckle as he scrolled through Keselowski's mobile device.
So what were they talking about?
"Well, he made fun of me because it's not organized," Keselowski said Friday at Phoenix International Raceway. "If you've ever seen Dale Jr.'s phone in action, he has I think at least 40 folders all full of different apps and games. There's no way he can use them all.
"I don't use but maybe one or two folders, and the rest is all on different pages. So he couldn't believe I couldn't didn't have them organized, and he couldn't believe I didn't have more apps. It was a whole new world to him."
What was Keselowski's comeback to Earnhardt Jr.'s ribbing?
"I told him I couldn't believe he wasn't on Twitter," Keselowski said.
The drivers later used the phone to look up the weather radar, since a rain shower was dancing around the track.
"We had some fun," Keselowski said. "It was great to have access to those things."