One Touch Mirroring is something new on the Xperia Z. With the latest SONY BRAVIA TV, you can now use NFC to handshake and deliver the contents to the large screen using WiFi Miracast. Below is a video which shows how it is done.
As it is still a prototype, there is a lag and breaking up in the transmission.
Alternatively, you can hook up the Xperia Z to the Sony TV through HML.