document.querySelectorAll("img[title]").forEach(img=> {
  const rect = img.getBoundingClientRect();
  const bodyRect = document.body.getBoundingClientRect();
  const scrollLeft = window.pageXOffset || document.documentElement.scrollLeft;
  const scrollTop = window.pageYOffset || document.documentElement.scrollTop;
  const $title = document.createElement('div');
  $title.innerText = img.title;
  $title.style.cssText = `
  position: absolute;
  top: ${scrollTop+rect.top+img.offsetHeight-bodyRect.top}px;
  left: ${scrollLeft+rect.left-bodyRect.left}px;
  background: #eeeeee;
  width: ${img.offsetWidth}px;
  padding: 1rem;
  box-sizing: border-box;
  z-index: 10000;
 `;
  document.body.append($title);
})