Artists, who have played with their own pareidolia first, know how to play with the pareidolia of the beholders of their works.
I incidentally found this in December 2017 as bycatch from my Snark hunt:
My first Snark encounter was in 2005. Then, after almost four years, I entered the Snark hunting grounds in December 2008. http://www.artandpopularculture.com/User:Goetzkluge could give you an idea where I was in 2010.
The image shows illustrations by Henry Holiday (from The Hunting of the Snark, 1876) and Marcus Gheeraerts the Elder (Allegory of Iconoclasts, aka The Image Breakers, around 1567): In the “mouth” of Gheeraerts’ “head” a praying priest is depicted. The shape of the priest also is visible in the “mouth” of Holiday’s vanishing “Baker”.
And there are more big heads.
2017-08-28, updated: 2022-10-21
Blurring images is low pass filtering images. An artist’s blunted sight can have the same effects like blurring with computerized image processing. Sometimes you need to get rid of distracting details in order to get the whole picture.
Before computerized image processing was available, artists use simple techniques to blur images. For example, looking at an image through a feather did the trick.
Blurring might help you to see things which you wouldn’t see with clear sight. It’s fine to try that with artwork which might have been intentionally created for such an exercise. But better make sure that it was an artist who created the face that is looking at you. I don’t know whether Mars ever has been inhabited by artists.
See also: Susana Martinez-Conde, Dave Conley, Hank Hine, Joan Kropf, Peter Tush, Andrea Ayala and Stephen L. Macknik: Marvels of illusion: illusion and perception in the art of Salvador Dali
2017-12-28, updated: 2022-02-02