Why can't I push the reponse data to an array?

Question

Building an express route for uploading images to a listing. The route controller uploads the images to an S3 bucket and responds with a data object. Within the data object is Location and this is what I want to push to an array. I can console.log(data.Location) and it works every time, why can't I push to the array of imageUrls?? No matter what I try pushing to the array(even a string I type) nothing happens.

Here is the route controller:

exports.imageUpload = async function (req, res) {
  //checks for files,
  //also checks that listingId is right length to not throw a CastId error in mongoose
  //idk if that is completely right to do
  if (!req.files || !req.params.listingId)
    return res
      .status(400)
      .json({ success: false, msg: 'No files given OR no listing ID given' }); //TODO change this for production

  const listing = await Listing.find({ _id: req.params.listingId }).limit(1); //returns array with listing being first index

  if (!listing || listing.length < 1)
    return res
      .status(400)
      .json({ success: false, msg: 'Listing does not exist' });

  //config for s3 bucket
  const s3 = new AWS.S3({
    accessKeyId: process.env.awsaccessKey,
    secretAccessKey: process.env.awssecretKey,
    Bucket: bucketname,
  });

  s3.createBucket(function () {
    const files = req.files;
    var imageUrls = [];

    files.map((file) => {
      var params = {
        Bucket: 'kret-static/listingImages',
        Key: file.originalname,
        Body: file.buffer,
        ACL: 'public-read',
      };

      s3.upload(params, function (err, data) {
        if (err) {
          console.log(err);
        } else {
          console.log(data.Location); //this works just fine no matter how many images
          imageUrls.push(data.Location); //why will this not do anything???????
        }
      });
    });
console.log(imageUrls); //always results in an empty array even though the data.Location is there
  });


  // //listing model method for pushing the images into DB instance
  // listing.pushImages(req.files);

  // try {
  //   await listing[0].save();
  //   return res.json({ success: true });
  // } catch (err) {
  //   return res.json({ error: err });
  // }
};