What Gene said. Go to the trash can at the bottom right of your screen it’s in the dock. Double click to open. Select all and restore them to photos.
As I replied to someone else, the trash is empty. There is nothing to restore.
I think OP commented on not getting much more space on the drive after moving and deleting all those photos. Probably because a lot of them are still on the drive but now in the "Trash" until they are either restored or the Trash is emptied by the user.
On a PC it is called "Recycle Bin", you set how large it can be and you set how long things stay until automatically deleted for good. Recycle Bin has "Restore All" or "Restore Highlighted" whereby you can restore everything or selected items. Trash must have something similar. So OP should be able to get many of the pictures back at full size, copy them to the other drive and then delete them, following which OP should empty the Trash. Then a lot of disk space will be completely freed up.
I think OP commented on not getting much more spac... (show quote)
Ah, this reminded me of the "recently deleted photos" in Apple Photo. I recovered 1300 photos, many of which are valuable to me. Thanks.
Unfortunately, the trash is empty. I do that frequently.
Oh, too bad. Maybe recovery software can get some of them back if the drive space hasn't been written over in the mean time.
I have used Recuva Pro on my PC. They don't have a Mac version but here is an article on 5 other brands that work with Mac. Some of them have a free trial version so you can see if there are files worth recovering but to actually recover them you have to go to the paid version. Well one the free versions will recover 1GB, pay to get more back.