Full size: http://imgur.com/ULmy341
Sometimes in public or at work, I want to use Siri, but don't want to talk to my phone. Even with the headphones in, people might think I'm on the phone, but if Siri messes up, repeating and over annunciating could draw attention. It would be easier to text Siri "Remind me to buy milk when I leave work".
I also thought showing my Siri history would be beneficial. I often ask something, like what time a movie is playing at a local theater, then hit the sleep button. If I forget what the other times are, I want to be able to go back and look, instead of asking again.
I already want to redesign the history part to be the actual results of your requests, just as it would look now if you had a lengthy back and forth with Siri.
Thanks to @Teehan+Lax for the iOS 7 UI PSD.