isotope/_includes/layout-change.js

      // change layout
      var isHorizontal = false;
      function changeLayoutMode( $link, options ) {
        var wasHorizontal = isHorizontal;
        isHorizontal = $link.hasClass('horizontal');

        if ( wasHorizontal !== isHorizontal ) {
          // orientation change
          // need to do some clean up for transitions and sizes
          var style = isHorizontal ? 
            { height: '80%', width: $container.width() } : 
            { width: 'auto' };
          // stop any animation on container height / width
          $container.filter(':animated').stop();
          // disable transition, apply revised style
          $container.addClass('no-transition').css( style );
          setTimeout(function(){
            $container.removeClass('no-transition').isotope( options );
          }, 100 )
        } else {
          $container.isotope( options );
        }
      }