Marco TempestThe magic of truth and lies (and iPods)

Using three iPods like magical props, Marco Tempest spins a clever, surprisingly heartfelt meditation on truth and lies, art and emotion.

http://www.ted.com/talks/marco_tempest_the_magic_of_truth_and_lies_on_ipods Marco mentions that his amazing technology that allows images to extend to other screens would be helpful in movie making. Why?