A guy like Musial had his card printed in multiple years. ESCO made a new run of cards every year but often reused artwork. So if a guy was there throughout the fifties and was good, he was in ten different print runs, at least. Depending on the year, the cutting and cropping varied slightly. if it really varied, the cards would be recognized as variations. The Jeff Heath, for example, has a really big variation:
Others are more subtle and the older catalogs did not reference them:
The Musial with the shade is a legitimate variation. Off the top of my head, Lemon has the same thing.
Even Paige has a variation:
My guess is they lopped off the bottom to get rid of the "An Exhibit Card" and ran it again.