deblan.io-murph/assets/js/app/quick-post.js

const QuickPost = function (w) {
  this.window = w
}

QuickPost.prototype.init = function () {
  const doc = this.window.document

  const images = doc.querySelectorAll('.quick-image img')

  for (let i = 0, len = images.length; i < len; i++) {
    (function (image) {
      const source = image.getAttribute('data-src')
      const loader = new Image()

      loader.onload = function () {
        image.style.backgroundImage = 'url(' + source + ')'
        image.style.backgroundSize = 'cover'
      }

      loader.src = source
    })(images[i])
  }
}

module.exports = QuickPost