You can order the elements with a function you supply. In the demo above, each item has a data-date-created and data-title attribute which are used for sorting.

<figure class="col-4@sm picture-item" data-groups='["city"]' data-date-created="2016-06-09" data-title="Crossroads">…</figure>

<select class="sort-options">
  <option value="">Default</option>
  <option value="title">Title</option>
  <option value="date-created">Date Created</option>
</select>

Demo.prototype.addSorting = function () {
  document.querySelector('.sort-options').addEventListener('change', this._handleSortChange.bind(this));
};

Demo.prototype._handleSortChange = function (evt) {
  var value = evt.target.value;

  function sortByDate(element) {
    return element.getAttribute('data-created');
  }

  function sortByTitle(element) {
    return element.getAttribute('data-title').toLowerCase();
  }

  var options;
  if (value === 'date-created') {
    options = {
      reverse: true,
      by: sortByDate,
    };
  } else if (value === 'title') {
    options = {
      by: sortByTitle,
    };
  } else {
    options = {};
  }

  this.shuffle.sort(options);
};