A clear cut case of Form follows Function. Leave a deforming force long enough and the body will accommodate.
When the lateral quadratus plantae (QP) is weak and the flexor digitorum longus pulls unopposed (relying on the QP to properly orient the long flexor pull) for too long the 4th and 5th toes and drift medially and spin inwards toward the midline of the foot (as seen in the photo). Then, as the 4th toe presses down on the fleshy pad of the 5th toe, over time the fleshy pad is pancaked and triangulated. Then, with repeated pressure a corn like hardness becomes of the tip of that triangluted tissue, it resembles a hard callus. A corn is a coalescing of the skin cells into a tighter formation, a reaction to fend off repeated pressure and friction. Form follows prolonged function. Shave these things down and they will come back, unless you get to the root source of the problem, which could be all the way up the chain.