I thought this was a pretty cool video. Targets are expensive these days and this may save someone tons of money. The only thing I'm not too excited about it hitting the plywood with an arrow, but it would take a few arrows before that target costs as much as a real 3d target. I'd also put a better BH target rather than hay bales. My arrows bury inside of bales.
The other thing I would mention is that if you have a projector, use that to put the image on the wood. That would save tons of time!