Topps started by printing these inset pictures with natural backgrounds. on many of them you can see trees, and sky behind the mini photos....then after a few printings they realized that they didn't look too clear with the extra noise in the background, so they doctored the photos to be a solid orange/pinkish color. That way, the coach picture would show up better. They made mistakes on a few of them with skimming off ears, etc when they placed the orange mask on the photo...so a handful have a third variation with the cropping fixed.
These are all mostly easy to find, and are quite easy to decipher when holding in hand
here's one nicked from ebay where poor lew burdette lost his right ear to the cropper.
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