Showcase uses the Core XenForo Attachments System (the attachments system handles things like resizing, showcase just has options to let you set those sizes different than the default attachments options).
The attachments system should be auto handling rotating (that was once an issue with IOS IIRC). As far as I know, there are no "rotate" functions that are part of the Attachments System (if there are, it would be something that all content types would have access to (threads, conversations, media, resources etc).
Thanks. That's what I'd assumed. And you're right, the images should orient correctly automatically. But we have users who some how manage to create images that don't self-correct (maybe the use some image software that strips the meta-info or they have really old cameras).
I picked up an add-on that will allow a user to manually rotate an inserted image but it only works in forum posts. It's not a big deal, just asking.
I've personally not seen it happen, but I have heard about it (and I've seen several posts about it at xenforo.com). I'll ask Chris D if he's seen any recent reports of it happening and what his thoughts are on it.
Being a car club that supports owners of vehicles more than 50 years old, we have a fair degree of content that was scanned. And because our previous systems totally sucked at dealing with PDFs, people tended to save and upload the scans as jpeg attachments. I can't put my fingers on an example at the moment, but looking at an electrical schematic or exploded parts diagram sideways or upside down hurts the head.