code: function(items) {
              for(var i = 0; i < items.length; i++) {
                  var heightToAdd = 0;
                  if(!isNaN(items[i].relativeHeight)) {
                      var height = items[i].element[0].getBoundingClientRect().height;
                      heightToAdd = items[i].relativeHeight - height;
                      var marginBottom = parseInt(items[i].element.css('margin-bottom')) + (heightToAdd > 0 ? heightToAdd : 0);
                      items[i].element.css('margin-bottom', marginBottom + 'px');
                  }
              }
          }
docs: Method that calculates items' "virtual" height depending on relative positioning