If the photo was rotated by a third-party application (such as a photo taken on a phone in landscape and then rotated to portrait) and then uploaded to the image manager it should post as intended. However, if the image is too large to be posted and needs to be compressed or resized through our image editor it will remove any previous changes done to the image such as rotations.
You can resize or compress the image through an app or website until it can post through our image manager to avoid this.