I don't think that qualifies for the parody tag as it has to be making fun of something, not just be based off something.
I think the artist made fun of the first AT-AT toy design, which looked very different from the film AT-AT... the head mostly.
That was probably because at the time detailed toy molds of that size were hard to make and very expensive. And the toy makers dedicated more budget for the electronics that the toy had, unlike the new toy versions which don't have any electronics but have superior sculpts.
Seeing that toy in the Hoth battle is actually very funny...