Can see this varies widely depending on the person. It has to do with data that an iOS device (iPhone, iPad) associates with any photo. The data, called "exif" drives orientation. It's usually not a problem apple-to-apple (though can be depending on the sending and receiving op system versions) as often as with iOS to Windows. Supposedly, the newest versions of both OSs are handling this better. One of a zillion articles and blog posts about this here for any interested. Can really be a pain.
Nope, wasn't trying to make guessing that po' boy's provenance that tough! :-)