

.with-after-image::after {
  content: "";
  position: absolute;
  top: 0;
  bottom: 0;
  left: calc((100% - 1350px) / 2 + 808px);
  right: 0;
  background-image: url('your-url.jpg');
  background-repeat: no-repeat;
  background-size: cover;
  background-position: left center;
  z-index: 0;
}