How to Sharpen a Knife With Leather and why it works.
 

Using leather to sharpen a knife, more commonly called "stropping," is a method that will allow a knife to take on a razor-sharp edge. Stropping is normally used on straight razors to attain an edge that can be used for shaving. The leather polishes the blade's edge and removes microscopic burrs or defects on the edge. In order for stropping to be effective, the knife should have been previously sharpened to a fine edge.

https://www.trails.com/how_811_sharp...e-leather.html

O.K. in simple terms what the leather is doing is taking the burrs from sharpening and re-aligning them straight. This gives the edge not necessarily a better cutting edge but a "cleaner cutting edge" such as in barbers razors and your home knives.
In the field your razor can be sharpened to do a decent temporary job of shaving your face by honing on your jeans... Hope this helps. :thumbsup: