I guess I must be easily amused. The truck in front of my car had "rotating" ads on the back and side. I was in awe.
Study the inset and its difference from the main frame.
LOL... ads are everywhere ... from tattos to t-shirts to banner tow aircraft.
If you can take a breath you are going to be sold something 24 hours a day, 8 days a week.
I saw one of these not so long ago . ..I found it intriguing and yet annoying . . .someone busy reading the turning side of a truck may not be busy watching me turn!