old photo or image files

From your description, it sounds like they don't have any extension on the files.

Ctrl-click on one of them and choose Open With Preview.

If Preview isn't offered, choose Other… then find Preview in the Applications folder.

check out GraphicConverter https://www.lemkesoft.de/en/products/graphicconverter/

you can get the trial version and use it for free. I'm not sure if it has a time limit. I consider this a must have utility. It has a list of file formats it can open, that is many pages long.

When you open the file, control click or right click on the file and a menu opens. Then you get a list of apps that might work. You may have to go to "other" and navigate to GraphicConverter. you should only have to do this once, then it will show up in the list.

Hello,

Terminal cannot open photos. Which file format are these photos in? Which “older Mac” did you transfer these photos from and what version of macOS does it run?