EXIF data - Export for Web

Here's something I find baffling.

  1. Open a .jpg image.
  2. Save as a .cpt.
  3. Export for Web as 1.jpg.
  4. Close the .cpt image and reopen it.
  5. Export for Web as 2.jpg.

The differences between 1.jpg and 2.jpg is that the latter is stripped of EXIF data and the file size is obviously smaller.

Useful to know if you want to keep the EXIF data with the .jpg (or not). Is there a simple explanation for this?