How to restore an image in which part of the image is covered with a red square but everything is fine on the preview?

Question

Image processing

They threw it off from the local "photo studio", it is displayed perfectly on the preview, but if you open it, a red square appears that overlaps the main part of the image.
Example:
Full size of the sent image without changes.

Answer 1

As such, no way.
When editing, the software did not recreate the preview, so there is such a difference.
The JPEG format does not provide separate layers.
Previews in low quality are stored separately in it.

Answer 2

The file just didn't get copied. If you look in a hex editor, then after the offset 0x90000 there are solid zeros, which is very unusual, they are displayed as a "big red square". The preview, as written above, is a separate picture at the beginning of the file.