Things don't always go as you wish they would, even at a trade show. For instance, you can forget to ship a critical item for your booth out. Or the game you're demonstrating might not do exactly what you were hoping it would...
I just happened to be walking by when this machine blue screened and I snapped this photo before they could do a reset. In their defense, however, the machine was in a drawer (to keep the presentation area uncluttered) and not well ventilated, which was common at many booths.