The specific point I want to bring your attention to is the visible pattern or color on the top surface of the tile called the glaze. The tile glaze has two properties to consider. One is the resolution of printing, and two is the frequency or number of pattern images available per box of tile.
The resolution pertains to the refinement of the printing process. Click on this image to see the close-up comparison of low resolution versus high resolution printing. This isn't a magnification but actually something you can see directly with the naked eye. The number or randomness of the printed glaze may only be noticeable when several tiles have been laid out together for comparison. If there low number of prints then you will see the beginning of a repeating pattern on the floor. Click this image for a closer look.
As the manufacturer increase the number of images then the pattern begins to repeat less. Seen here is a medium randomness.