This is done for several reasons. (1) Logos of some tannery on a brand new sole are ugly. (2) The soles or heels that are used can be old, and a bit dry, especially if they're kept in an arid closet in the back of the shop. A cream/moisturizer is applied liberally to the leather, and seeps in, conditioning the leather and thereby making it more durable, more flexible, especially in cold weather. (3)It allows a new finish to be put on, polished and shaded to blend in well with the rest of the sole. Yes, we actually are that anal.