Dupe glitch with Item frames & comparators

By placing 3 blocks into a 2 tall L shape on the border of a chunk, facing south and placing a comparator onto the out facing block and an item frame on the 2 high wall on the other side and exiting and re-entering again and then destroying the item frame causes the item frame and whatever is inside it to duplicate stacks of said item.

Attachment is a visual description on how to perform the glitch.