I like that poster. That is one very plausible (to me) explanation for the various stories and sightings. However - Satan usually disguises his actions in “good” things. The “apple” from the tree of knowledge for example. “Why knowledge is good!”
So I’ll have to think on that use of the hideous face of the “gray” alien. Although I guess that alien in the Twilight Zone “To Serve Man” was pretty scary at first.