External HDD photo library size

[bwfc0907]

I’m completely confused by the library size.

Previously I had 70k photos SIZE 625GB on an external 1TB external HDD drive. A back up was kept on a partition of my time machine (a different external drive - this was just a straight copy of the 1TB photo library).
Under Catalina the original library on the 1TB external HDD would not open so I formatted the 1TB external drive and intended to copy the back up to that drive to fix the issue.

For some reason the backup does open but I cannot copy to an external drive as it says not enough space.

i am confused as Catalina shows the backed up library as 650GB but when you show package contents the folders total in excess of 1GB and more items than on my original external drive.

What is in each of the folders?

i have purchased 2TB iCloud to back up to that but until I can get the files on my external 1TB I can’t back them up. If I try to use the partitioned copy of the library it says I need to optimise my Mac as the photos will not fit.

A screenshot of the back up contents package is attached. All other folders of the back have minimal files in them.

 

[Ledgem]

One quick tip - to take a screenshot of something on your Mac, there are three keyboard commands you can use. The only one you probably need is command+shift+5, which gives you a bunch of options and allows you to take a screenshot of a specific part of your screen. The older commands were command+shift+3 to take a screenshot of your entire screens, and command+shift+4 to take a screenshot of a particular selection (but using 5 instead of 4 is much more user-friendly; I believe it was introduced with macOS Mojave). Screenshots should appear as a PNG file on your desktop. I have to admit that I can't really read much from the photo that you shared.

Two questions:
1) I'm assuming you're not using a referenced library, and all files are kept within the Photos library?
2) Has this library already been opened under macOS Catalina? It undergoes a bit of a conversion process when opened for the first time.

As far as I know, "originals" corresponds to your original photo files, while "resources" contains things like thumbnails and possibly edit data. I don't have a great explanation as of now for why there's a file size issue with fitting it onto your external drive.

 

[bwfc0907]

Original photo updated, apologies