Cannot move imported photos from Photo Library

I see the imported pics in a folder within the Photos Library, but when I select all and try and move them ANYWHERE on my iMac, or to an external drive. It just says "preparing to move, and that's it... nothing else (snapshot attached - taken 8 mins after I tried to transfer for the 20th time).

The new imported images in the master folder are most of the time in use by Photos, even after you quit Photos. Photos is busy with indexes the new photos properly and scanning them or analyzing them for categories, places, faces. This takes a long time. photos may also be syncing with iCloud. As long as Photos is using the items, the Finder will be waiting and cannot use the items in the Master folder. An if you previously damaged the Photos Library by removing items behind Photos's back, Photos may be still trying to repair the damage.

The safest way to get photos out of Photos is to select them in Photos, for example in the All Photos album, and then to use "File > Export > export unmodified Originals".

And if you are not using Photos at all, other than for importing from your iPhone, follow Terence Devlin's advice, when you import new photos from the iPhone and use Image Capture instead of Photos. If the primary system language of your Mac is not set to English, the Image Capture.app may have a different name. But you will recognize it by the icon - a camera and prints.

Why on earth are you using Photos for this task? If all you want is to get files from your phone to a specific location on your Mac then use the app designed for the job: Image Capture. It's in the Applications folder.