.peg file Photo fails to import, can't delete from iphone

"...unreadable...unrecognizable file" error when I try to download a file from my iphone to my computer.

The file is not corrupt, it's just a standard jpg misnamed to .peg.

But Image Capture doesn't see the file.

The error message includes the name of the file, but a search doesn't find the file.

How can I delete it?

https://discussions.apple.com/thread/8264300

This doesn't work because I don't see the file thumbnail.

iphone 5, iOS 10.3.3