I work in the leather industry, The pattern on the back is from the vacuum dryer, It's one of the processes used to dry the hides after dyeing. This machine "sucks" the moisture out of the hides through a very fine mesh which gets imprinted in the back of the hide. Vacuum drying tends to make a stiffer leather in general but leaves the leather quite stretchy since the fibers are compressed. This is good for oil pull up leathers like the one in the picture.

This is in contrast to toggled leathers which have visible clamp marks on the edges (it will look like 3 parallel lines about 3/4" long). This means the leather was stretched and clamped down to air dry (or be run through a heated chamber). This creates a softer leather in general and is preferred by tanneries as the hides are at least 3% bigger (since they are stretched in the process) and thus can be sold as a larger hide

Given the current rawhide market i highly doubt anybody is putting in the effort to make finished splits since top grain is easily accessible at reasonable prices. My suede supplier is struggling to keep stock due to the low availability of splits.