How do I copy a photo from photos app to an external USB key
It's all in the question. I want to be able to copy any arbitrary number of photos to a USB key (i.e., to jpg files) or external non-HSF disk. In other words, OUT of the photos app.
My preferred way would be go into a terminal, cd to the appropriate directory and use cp to copy the photo. But I suppose macOS will not let me do that. So something equivalent will be just fine.
TIA.
MacBook Air, iOS 10.1.1, In fact, Sierra 10.12.3