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:
In this image one of the elements has been marked (orange frame) which Henry Holiday borrowed from a 17th century painting (by an anonymous artist). This might be a bit different from the borrowing described by T. S. Eliot in 1920. In the example shown here, the borrowing of the pictorial allusion is inconspicuous. It doesn’t enrich Holiday’s illustration. It’s only purpose might be that of a signpost pointing to another work of art.
2017-09-27, update: 2019-02-25