This dove holder is made so that the dove is always snug and secure. All you have to remember is to load the dove tail first, making sure that the dove's legs are extended back toward the tail. Now fasten the Velcro, adjusting it so the dove is snug and secure.
This is one of the best ways of fastening the "loop" of the holder to the inside of the jacket. For years dove workers used tape, pins, clips, etc... This Version using velcro, you will find, is the easiest and most reliable.