code: def get_all_images(self):
          
          self_imgs = self.image_set.all()
          update_ids = self.update_set.values_list('id', flat=True)
          u_images = UpdateImage.objects.filter(update__id__in=update_ids)
  
          return list(chain(self_imgs, u_images))
docs: Returns chained list of event and update images.