Moultrie trail camera

I have a few of the moultrie p150 trail cameras. They function fine and seem to take a bunch of pictures. I have an iPhone and usually just transfer the pictures straight to it through a portable usb device (bone view and lighting device for iPhones.) For some reason the pictures on the SD cards in the p150 trail camers do not come up on my iPhone when using the usb device (the only pictures to not ever come up.) but when I put the same SD card in my wildgame innovations trail pad viewer they pull up just fine. Any suggestion as to what may be causing this?
I really want to put them on my iPhone. It's where I store all my hunting pictures for organization and such.
I've also tried taking the camera out of panoramic mode assuming that the pano pictures were just too big of a file size to import on my phone. It still did not change with the camera set to single zone pictures.

Thoughts:

The iPhone might be expecting the pictures from a specific folder and the trail camera might be storing it in another.

The trail camera might be saving in a file format (or sub-format, if ever) not recognized by the iPhone.

Compatibility issue? Try another card?

One possibility is that the photos are not JPEG or JPG files, but instead either DNG or some proprietary file format. If you can get the photos in question onto a computer, you could then right click on one and see what the file type.

Another possibility is that the photos are in one folder, but your device is set up to only look for files in some other folder/location.

I agree with Frank but another possibility is that the iPhone can't handle the file names - have a look at the SD card on a computer and make sure there's only one "." - look for anything else that's not alphanumeric.