someone mailed the item/s to them and their inventory was full, so it forced the items to fall on the floor. If that ever happens, it automatically protects the items so people cant steal them while the person tries to empty some inventory space to pick it up.
I am always seeing little turd piles like that in shops where people dump stuff to make room for items. A better way might be to make you wait to get your mail until you are on your Residence if your Inventory is full. Otherwise it is like stepping on a land mine.
