code: def _new_placeholder_pic(self, image_file):
          
          rId, desc, image_size = self._get_or_add_image(image_file)
          shape_id, name = self.shape_id, self.name
          pic = CT_Picture.new_ph_pic(shape_id, name, desc, rId)
          pic.crop_to_fit(image_size, (self.width, self.height))
          return pic
docs: Return a new `p:pic` element depicting the image in *image_file*,
          suitable for use as a placeholder. In particular this means not
          having an `a:xfrm` element, allowing its extents to be inherited from
          its layout placeholder.