Google Drive API to search images

I recently started to study the Google Drive API. I'm able to list all Drive files and have access to all of their attributes. However, I was asked to search only for image files.

What did I do? I played the search code inside a JavaScript:

if(file.extension === 'jpg' || file.extension === 'png')

But there you go. My search is parsing all the drive files and listing only the .jpg and .png files, making my search very poorly optimized. I wonder if anyone could help me. I want my search to scour the Drive and return only the img extension files. Here is the code that searches the files stored in Drive.

function listFiles() {
    gapi.client.drive.files.list({
      'maxResults': 1000
    }).then(function(response) {
      appendPre('Arquivos:\n');
      var files = response.result.items;
      if (files && files.length > 0) {
        for (var i = 0; i < files.length; i++) {
          var file = files[i];

            appendPre(file.title +' - '+ file.embedLink);

Follow the API link link . Thanks in advance.