Actually new cars sold in CT must meet the California emissions standard. Since I bought mine in Michigan, I was able to register it in CT.
There are 13 states that subscribe to the California requirements. I live in Mass which is one of them.
I also believe the cars are all exactly the same and the reason that they put a California sticker only on those cars that are being shipped to the 13 states that subscribe to California requirements has to do with certification fees that have to be paid to CARB for each approved car sold.
My 13 Focus ST came with a non California sticker. A few months after delivery I got a letter from Ford with instructions to cover the existing sticker with the enclosed California sticker.