How to open a PC file on a mac

I have a camera flash drive with some photos on it - all JPG.

The camera flash drive was modified on a Dell PC with Windows to create three separate file folders with names and then all the photos were segmented into one of the three folders.

Each new folder now has a few hundred photos.

When we try to open the flash drive on our Mac it show a "no files found" message.

But when we go back to the Dell they are all there.

How do we get the Mac to open or recognize the files on this camera flash drive?