By definition useless machines are...well... useless, case closed :) In all seriousness though, a useless machine is a machine that undoes anything you do it. Typically these machines are simple boxes with one or more switches. You turn the switch on.... the machine turns it off. Simple as that :)
After watching the video I found myself connecting with this inanimate object almost like it was a human. Not in the sense that it looks anything like a human (obviously), rather that it thinks and feels like one.
Achieving this anthropomorphic effect is easier when your game involves life-like 3d models, but what about if your game is more abstract? Maybe one where the antagonist is a just a red square. How can you make a red square feel life-like? Well I think this video shows us how.
In the video we see the machine respond to the same action in several different ways and with each response we see a different emotion. The creator managed to achieve this by simply altering the motion of the arm.
The arm moving slow might convey hesitation or fear, while a fast arm movement might communicate a greater sense of purpose in the machine. Add a nice hold after the fast motion and now you have frustration.
In the same way, giving your AI these slight variations in movement can give even the most simple AI emotion and personality. And remember, anytime you can make the player feel something you've helped pull them deeper into your game!
If you have any other tips to help make AI more life-like I'd be interested in hearing it in the comments below :)