Imagine you can program a computer to recognize those apple patterns and do a similar job. The computer can simultaneously watch over many conveyor belts that you can't. Then... they know you would pick the same apple... they have a fast robot to grab that apple before you can from the conveyor belt.
+1 And another robot periodically comes along and stands in front between your robot and the conveyer. They are invisible and your robot only knows they are there because apples start disappearing.
Kinda like this? <iframe title="YouTube video player" width="480" height="390" src="http://www.youtube.com/embed/4wp3m1vg06Q" frameborder="0" allowfullscreen></iframe>