When you have uploaded the image and published it inside the gallery and suddenly realize that images are rotated in the wrong side. So to make them show normally you need to
- Open your images in the WordPress Media Library
- Click “Edit image”
- Click Rotate
- Save the changes
- Back to you gallery
- Click Save to renew changes
- Clean cache in you cache plugin
- Clean cache and cookies in your browser
- Reload the page with published Gallery
These changes will also apply to the picture in your gallery and everything will look as it should.