static function thumbnailFromUserId( $user_id, $size ) {

		$image_url = get_user_meta( $user_id, 'pb_catalog_logo', true );
		$book = get_active_blog_for_user( $user_id );
		if ( $book ) {
			switch_to_blog( $book->blog_id );
			$image_url = \Pressbooks\Image\thumbnail_from_url( $image_url, $size );
			restore_current_blog();
		}

		return $image_url;
	}