Does :before not work on img elements?

Question

I\'m trying to use the :before selector to place an image over another image, but I\'m finding that it simply doesn\'t work to place an image before an im

Answer 1

::after may be used to display the fallback image of an image

---

See the example below, first 2 img tags are point to the broken urls. But the second one displays the fallback image instead of the default broken logo from the browser. However, I'm not sure this's any practical, I find it kind of tricky to get it to work right.

img {
  position: relative;
  display: inline-block;
  width: 300px;
  height: 200px;
  vertical-align: top;
}
img:not(:first-child)::after {
  position: absolute;
  left: 0; top: 0; right: 0; bottom: 0;
  content: "<" attr(alt) "> NOT FOUND";
  border: 1px dashed #999;
  background: url(https://cdn.dribbble.com/users/1012566/screenshots/4187820/topic-2.jpg) center/100%;
}