Flip phone sends photos as slide show?

Using a method that has always worked in the past, I send 4 images captured with a flip-phone camera to my email as a “message”.

Now,unlike in the past,for some unknown reason, in gmail, those multiple images are labeled as if they are a single file.

Downloading that file to the “home” folder on a Mint 18.2 desktop, it shows up as a video, with no thumbnail, and when trying to view the contents by clicking on the file, , a “media player” is automatically opened, as if the contents are a video, but it cannot play the file(s).

I tried opening the thing (whatever it actually is) in various apps like VLC, GIMP, after adding an appropriate extension – .jpg, .png, .mp4, .flv….. nothing I can think of makes any difference.

I tried sending photos without text; same result.

I found a claim that if I “Disable “Live” features: If your phone supports a “live” or “motion” photo feature (similar to iPhones), ensure it is turned off in the camera settings, as these are captured as short video clips.”

But the phone is not set to “video’, it is set to “photo”.

I found this as well:

” Check MMS Settings: In your phone’s messaging settings, look for an “MMS Creation Mode.” If available, set it to “Restricted” or “Warning” instead of “Free” to prevent automatic conversion to non-standard formats.”

I looked all around in my phone for ways to change the MMS settings as suggested, but the option does not appear anywhere I can find it.

Is there a conversion program that could retrieve the images?

Any other insights MOST welcome!!!!!