I have no idea. It seems to me that every card in the set is already a variation since the logos have to be removed.
But being the good little collector that I am, I tracked down both.
The card on the left is that base card and the one on the right is the variation. One road uni, one home pinstripes, no logos.
But wait, there's more!
We get a name variation too, going from Ernie Banks to "Let's Play Two." The problem is that every other player with this variation has their nickname on the card. Babe Ruth became the Sultan of Swat. Honus Wagner is the Flying Dutchman. Nolan Ryan is The Ryan Express.
And why is Ernie Banks called Let's Play Two? That surely is not his nickname. But Panini can't use his actual nickname of Mr. Cub. They'd have to call him Mr. Chicago. So they used a catchphrase instead of a nickname. It would have been better to leave Ernie out.
Or use Billy Williams, Sweet Swingin' Billy.