To reproduce:

* Select file #1. This file should have an id3v2 tag and should contain one or more cover images (2 in my case)
* Invoke "Tag Copy" through right click on file #1 or by pressing CTRL+C.
* Select file #2. File #2 should not contain any cover images.
* "Tag Paste" the tag contents to file #2 through right click or by pressing CTRL+V.
* Invoke "Edit->Undo"

The cover image(s) will remain in file #2.