Just click on the item after you added it to your picture. A little menu will appear, were you can choose to delete, flip or move it. Deleting and flipping works right away, but after you choose to move the item you have to click on it again to drag it. Keep the mousebotton pressed and move it to a different position. When you release the mouse button the item will be dropped.
KNOWN PROBLEM: Unfortunately it can happen that the little menu cannot be seen if another object is in front of it. So you have to move or delete this object first so it does not hide the menu anymore.
Posted in: 2) BASICS: How to use the SP-Studio