if not is_picture:
books_qs = books_qs.exclude(common_slug=instance.common_slug).exclude(ancestor=instance)
books = Book.tagged.related_to(instance, books_qs)[:max_books]
if not is_picture:
books_qs = books_qs.exclude(common_slug=instance.common_slug).exclude(ancestor=instance)
books = Book.tagged.related_to(instance, books_qs)[:max_books]