Every operation that makes a change to a PhotoPackage document is completely undoable, and the number of undo steps that can be performed on a document is unlimited. And for every undo operation that is performed, a corresponding redo operation will put it right back in case you change your mind.
With unlimited undo/redo capability, you have the freedom to experiment with different image placements and print orientations. You can even add the same image to a document more than once and try different approaches for each pose to see what works best, then remove the unwanted ones just before printing the package.