gistfile1.txt

// original

 function updateImage(){
    square_urls.map(function(urls){
      urls.map(function(u){
        console.log(u);
      });
    });
  }
  

//pseudo code

 function updateImage(){
    square_urls.map(function(urls){
      // url = < pick a random url from urls >;
      // imageTag = < find the image tag using jquery >;
      // imageTag.src = url;
    });
  }