You don't need to do any experimentation to know that a full-color receipt with lots of black on heavy stock is going to use more resources than thin thermal paper.

Reducing waste is like performance optimization - you should only do it once your code is correct. The original poster just paid $1000 for a meal probably consisting of fish that was pulled from the ocean on the other side of the planet 12 hours ago. The resource cost of acquiring this food, preparing it, and operating the restaurant will dwarf the cost of a nice receipt. If you prefer, they could hand write it on nice post consumer recycled stationary to save some "trees".

But, that's his whole point! He's saying that it's incongruous and inadvisable to cheap out on the design and production of the receipt when it's one of, if not the, final impression a diner will take away from your restaurant.

Ok, and that might work when it's a $1000 meal, but not for Starbucks.

Also, why does the receipt look like an iPhone app?

Um, because the iPhone is cool? Also note he said it was more a concept, not what you would actually impliment.

That's not as obvious as you think. Thermal paper costs more to make than regular paper.

I bet it costs less to print solid black on regular paper with a laser printer, than thermal paper.

Ah, I see what you're saying. I read "waste" in terms of ROI not gross resources.