I have a few tips. First of all, the patter could have been much better, next time, try and script! It will let everything flow a lot better. Also, you kept saying it was YOUR phone, when moments before you said it was your Uncle's phone. Just some continuity issues there. I also didn't see a real reason to have your spectator place the phone on the table. It would have been more natural if you just placed it on the table yourself.
So next time, try and script your performance, it will flow better and more things will make sense.
Mitchell