Haven't you wondered this yourself? I've always chalked it up to George Lucas not realizing in 1977 that he'd actually need to come up with a sequel or two to Star Wars. This Twaggie was illustrated by David Collier from a Tweet by Bad Bad Leeroy Brown. See more illustrated Tweets at Twaggies. Link
It's like comparing a telephone doodle to a classic painting...you cóuld, but it's not really logical to.