A mini cruiser has a lower top tube which has a greater pitch backwards then a standard cruiser making the seat-tube length much shorter, which suits a smaller rider.
If you think about it in new school term it get confusing as its very close to a modern day cruiser/or dirt jump frames with the much shorter seat-tube.
But back in the day people sat down on the seat, therefore full size cruisers had a longer seat-tube.
Some mini cruisers are also designed to take a skinny rim/tire.
