Copy can be done between 2 Normal folders objects or between a Shared and a Normal folder. Shortcut's can be done between a Shared folder and Normal folder.
For exmaple if u have an ObjectA in FolderA. If u want a object similar to that in FolderB. U can just Drag the object from FolderA to FolderB. These 2 Objects will behave independently. Means changes in FolderA object won't influence the copied object. Assuming that FolderA and Folder B can be either Normal or shared folder's.