Best you will have is you will have is someone trying to genuinely see what you can do, worst is TRYING to fail you to make themselves look better. Typical techniques that are used for this .. A rubbish machine or Imac with only 10 gigs of scratch space left. B a deliberately incomplete brief, and then saying yes i SAID THAT, when something different happens. C technique well used by Tapestry, telling someone that the test they are doing is actually a piece of client work which has to be out that day, giving no feedback, then analysing the work to according to Photoshop 5 best practices. In these ways its really quite possible to nail even the most talented bastard that comes through the door.