I’m pretty certain this is a bug and one that’s going to be resolved soon if I’m reading the github PR’s and commits correctly.
Edit, and by resolved I mean I believe it should be consistent throughout the app. Some people actually like the different font sizes, though, and they might be out of luck.
This sounds like one of those deals where the picture orientation is being determined by metadata that may be getting stripped when you post. I would file an issue on GitHub and include a sample image, if possible.