shuffle.js

function shuffle(shufflearray) {
  var i = shufflearray.length;
  var j;
  var temp;

  while(i-- > 0) {
    j = Math.floor(Math.random() * (i + 1));
    temp = shufflearray[j];
    shufflearray[j] = shufflearray[i];
    shufflearray[i] = temp;
  }

  return shufflearray;
}

$(function() {

  var cardsubset = shuffle(cardarray).slice(0,10);
  var $container = $('<div>');

  cardsubset.forEach(function(element, index, array) {
    var $img = $('<img>').attr('src', element.card);
    $container.append($img);
  });

  $('.card-images').append($container);

});