"Good" Info Designed Unexplained

I was about to applaud this McDonald's french fry box and the nutrition information design until I really started to look at it.

I eventually figured out that the gray shading represented percent of daily allowance, but what do the dotted lines signify? And what's up with the iconography? Granted, I'd be hard pressed to come up with an icon for carbs, but maybe they should have taken the easy route the way they did with "Cal."

Fortunately, the fries still tasted as awesome as ever.