I don't like that Twitter makes the source device used to make a tweet visible. It's nobodies business but mine whether I tweet from my Android phone or my desktop browser (I don't own an iPhone, nor do I have staffers tweeting for me). I guess Twitter has good reason to care what device I'm using, so that if something goes wrong they can trace why, but that's a compromise: ideally, even Twitter's server team really shouldn't know that.
It's snafus like this, unfortunately, that will lead to them hiding that info, instead of privacy concerns about everyday users.