I have a different card reader for my laptop because the laptop is not a Mac. I have no difficulty opening photos on the laptop.
When I plug in the card reader, that I purchased for the iPad, I see a message that an accessory is connected. However, I am unable to find the card reader when I check in Files. Perhaps this is an issue with the card reader & not the SD card. Or maybe it is an issue with an older user that isn't very tech savvy.
I had hoped to be able to preview & sort photos while traveling and without packing my laptop.