The camera adds an orientation tag to the image's Exif metadata.

Set orientation tag to normal after rotate/flip: the auto-rotate option automatically corrects the orientation of images taken with digital cameras that have an orientation sensor. If your camera routinely gets this orientation information wrong you might like to switch this feature off. The image will then be rotated on disk and the tag will be reset to 'normal'. If you want to permanently rotate the image on file, you can click with the right mouse button on the thumbnail and select Auto-rotate/flip according to Exif orientation. It will not actually rotate the image file, only the display of the image on the screen. Show images/thumbnails rotated according to orientation tag: this will use any orientation information that your camera has included in the Exif information to automatically rotate your photographs so that they are the correct way up when displayed.

The digiKam Metadata Rotation Behavior Settings Page ¶ If the box Read from sidecar files is checked, digiKam will only read the sidecar while ignoring the embedded metadata.

Exif tool windows