I have a MacBook Air and just updated to macOS Sierra, which automatically installed the "Photos" app to replace my old "iPhotos" app. As I scrolled through the "Photos" app sidebar I checked to see that all of my photos were there in the "Photos" folder (at the top of the sidebar). Then I scrolled down to the "Recently deleted" folder and to my horror saw a huge number of my images shown under the advisory that these photos would be permanently deleted in 28 days! They are photos that I didn't delete from iPhotos or Photos, and I don't want them deleted. I looked again at the "Photos" folder and saw that those same photos — the ones destined for deletion in 28 days — were also showing up in the "Photos" folders. I don't need two copies of them but I am wondering if they are safe if I see them in the "Photos" folder?
Now I did keep copies of my images both in my old iPhotos app and in another photo app (called My Pictures), and I did recently delete a large number of them from my "My Pictures" file to get more disk space, but I didn't delete the duplicates of those same photos from my iPhoto files. Is it possible that the photos I now see as listed for deletion (under Recently Deleted) are those duplicate photos I deleted from my My Pictures folder?