Mac screensaver photos displayed upside down or sideways

The Screensaver seems to show Originals from the Photos Library rather than the edited versions. This may be because the edited versions of pictures in Photos don't actually exist-- they are recreated on the fly in the Photos app by re-applying the editing steps to the original file each time you want to see them.

Instead of relying on Photos, I made an album of pictures I want to see, and exported those to a folder in the Pictures folder, and I use that for the screensaver. I am using a 13" Mac Air whose screen is 2560 x 1600 pixels, so I used the File>Export>Export nn Photos dialog to save images with a maximum width of 2560 pixels.

If I were really worried about file storage, I would maybe reduce the quality of the jpeg compression-- I probably couldn't tell the difference. If Photos had to keep separate pre-configured pictures for screensaver, it would probably take up at least this much storage space, anyway.

If you want, you can leave feedback for Apple here:

Feedback - Photos - Apple

did you have to rotate image after importing it to Photos? There is not yet an easy solution. The Screensaver is still having the bug, that it is only showing the original image files, not the edited versions. To be able to use the edited versions in your screensaver you would have to export the edited version as new file, then reimport the exported file and use this new image in your album for the screensaver.

Or export the complete album to a folder and use this folder as the source of the Screensaver.