They are/were shoes made by the shoe companies to show possible purchases. Always small sizes. Some were ordered others just to “exciting and different “ to sell
Always got big compliments on them as they were various colors or shapes that were on the edge. I had 100s of pairs of shoes as they were cheap. Seldom paid more than $5 pair
That explains why I'm not familiar with them. I haven't worn shoes in a small size since... oh, maybe toddlerhood!