My wife bought the GR3 a while ago for taking photos.
Even though smartphones take good photos these days, the GR3 still produces much better images, perhaps due to sensor or technology differences, so I've been using the GR3 for my reviews.
However, I usually transfer photos via SD card, but I accidentally took photos without the SD card inserted, saving them to the internal memory, and I couldn't figure out how to transfer them to my MacBook.
Searching around, I found that you can transfer wirelessly to an iPhone via the built-in Image Sync app and then move them back to a MacBook, but... I failed with that too.
I tried connecting via USB-C cable, but it failed..
It wasn't recognized...
After being so frustrated, I found an interesting post on an overseas forum..
Huh? Is this the filetransfer that is often used when copying APK files for Android development on a Mac ?!?
Yes, surprisingly, the GR3 allows you to copy internal files to a Mac using Android File Transfer.
Android File Transfer
https://www.android.com/filetransfer/
I hope this tip helps those who are struggling like me and don't know how to transfer files from the GR3 to a Mac environment.