The one on the left is the 7-up can used in the United States. On the right, the Canadian version. (I think the rest of the world uses the design on the right as well.)
The U.S. design is holding on to the shadows and highlights that are typical of 2000s design while the other can has flattened and simplified the design. I'm particularly fond of the red dot doing double duty.an article on the new 7-up design and expresses a preference for the 1977 version of the can.
This sent me on a Google search that turned up an even more extensive history of the 7-up cans -- plus histories of Pepsi, Coke, Dr. Pepper and more.