I don't consider them as variation in manufacture, Doug. The design is not a hologram. There is a pattern of fine dots on the inlay and the clear plastic overlay has a similar pattern of dots from the texture of the mold. When these are accidentally aligned perfectly, it looks like the fourth chip in your scan. With any other alignment, what is called a "moire pattern" is created by optical interference between the inlay pattern and the overlay texture. Since there can be an infinite variety of optical images resulting, I don't call these varieties. Several other chips exhibit this phenomenon, including those from the closed Caesars Tahoe. There are other discussions of this effect on the bb, including a comprehensive one by GregS a year or so ago.