I thought one of the additions to iOS 6 was being able to attach items from within an email. I don't see how.
It's a half-backed "feature" that doesn't really address the pain of writing e-mails in iOS. You hold down on the text area in the e-mail, then on the pop up, scroll to the right, click attachments. But you can only attach pictures, not files or stuff from other apps. Apple's e-mail really sucks if you actually want to write anything more than a quick blurb.