If you take a picture with a modern camera, your camera will save the device orientation in the exif-metadata. See exif-orientation for more informations.
Since v3.4.0, JoomGallery is able to auto-rotate images during upload based on the exif-orientation metadata.
Your problem will therefore appear, if you tooka picture with a modern camera or smartphone
and
the settings of JoomGallery are set to auto-rotate during upload
and
you manually rotated the image locally before upload without reset the exif-orientation metadata.
Possibilities to resolve the problem
- deactivate auto-rotate during upload in JoomGallery (you need to be admin)
- dont rotate the images before uploading
- if you rotate images, reset the exif-orientation
