A bug that we identified during testing and believed to be one that wouldn’t present itself in the actual final build, has proven to be a real bug – you can read the ticket details here.
What essentially happens is that on Posts when you add a photo, if you are in portrait mode, the photo gets rotated in the published version of the post. When in Landscape mode adding or taking photos get handled properly. Photos that are added to Pages work just fine as well.
We are very sorry that this happened and are working on a fix that we will push out ASAP.