If you select several objects to replace, Designer distributes Clipboard objects to replace selected objects. The first object in the Clipboard (from back to front if no reordering has taken place) replaces the first original object, the second Clipboard object replaces the second original object, and so on.
Select the Group Clipboard Objects option to replace each selected object with the entire contents of the Clipboard.
If you have several objects selected but only one in the Clipboard, each selected object is replaced with the Clipboard object.