Publii apparently strips exif info from .jpeg image files, specifically orientation. The exif info is there in the original file. When I upload the file, the original retains the orientation. But the resized images in the responsive folder are missing that data, resulting in photos that display sideways.
This has been brought up twice before:
https://forum.getpublii.com/topic/rotating-images/
https://forum.getpublii.com/topic/publii-rotates-images-during-upload/
The first appears to be a bug report that was mistakenly interpreted as a feature request. The second is a bug report I submitted in January. In that thread, you said you could not reproduce the behavior. Can you recheck, and make sure you check the responsive images folder? In my earlier bug report, I specifically mentioned that the “large file” displayed correctly while the responsive ones did not. I’m not sure if you noted that part of the report.