"The filter's algorithm works perfectly and it looks well alredy but we are not done yet. In this AJAX tutorial we will add the a new list item to the filter, I will just name it "all" and when it's clicked, all elements should be displayed. Otherwise there is no way to go back to the state of viewing all the images without reloading the page."
http://www.mybringback.com/tutorial-series/13911/36-jquery-tutorials-filter-going-back-to-the-original-state/