A recent New York Times article tells us the show's creator, Matthew Weiner,
inspired by a childhood memory of lush, painterly illustrations on T.W.A.
flight menus, wanted to recreate that look for this season’s print campaign.
It
could be we are thinking of a different era, but the Mad Men finished art looks
more like a rough indication than any of the “lush, painterly illustrations” we
remember from back in the day.
Click on images to enlarge.

On the other hand, a reader has just brought this to our attention:
Dear Edwina... I thought it was a Bob Peak ripoff:
