I saw that, too - I'm a pretty solid ~20% tipper. I might fudge it down a little if the service isn't all that (think 18%) - any lower requires the server to be really bad, and below 15% is only if they're largely absent or openly hostile.
What I want to know is why someone would expect a 20% tip on a take-out order??? IIRC, a tip is a gratuity for service received, and if I'm getting take-out, there's no service received. (Although I have been known to add a buck or two for a place I know to be very friendly, offering water while I wait for my food, etc.) (I also think Prudie's a bit off adding $5 to cover the take-out containers and a bag. 1) No way should they cost that much, and 2) The restaurant should be taking that into account when figuring costs and determining prices, and 3) Giving the server an extra $5 tip is not really offsetting the cost of the containers.)
Am I way off base, is tipping 20% now the norm regardless of actual service received?
Of course, if serving staff were paid a living wage to begin with, we wouldn't need to have this discussion, but that's another debate entirely.