As a retired redleg I'll take a shot at this one.
DPICM stands for Dual Purpose Improved Conventional Munitions. Each submunition is a anti-vehicle shape charge. Fairly good aginst thin skinned and light armor vehicles. Possible to do damage against heavier armor but truly it would be a lucky shot. The submunition also fragments to act as an anti-personnel munition. Because they cover a wide area they are devastating against personnel.
The shape charge has a small ribbon attached to the back and the detonator. This ribbon keeps the open end of the shape charge oriented toward the ground. try it with a small block of wood and a ribbon. If you tie it on one end and toss it up the end without the ribbon will hit the ground first.
Generally, the larger the munition the more submunitions it carries. There may be some difference in the size of the submunitions between calibers and countries. There is a balance between coverage and effectiveness. I hope that answers your question without getting into sensitive areas.
