I've only seen the illustration of the guys with "book bags" here on this site - I think it might have been maybe in an old JW calendar or something not widely distributed.
But there are definitely many illustrations of 1st century Christians (without bookbags) actually standing at the entrance of a house, while the "householder" leans against his doorpost with his chin in his hand, listening intently.
As if 1st century Palestinian peasants had time to hang around in their houses (maybe they were playing video games?), and it was not at all life-threateningly suspicious for random out-of-town strangers to knock on doors of residents.