Anon thought this was a strange depiction of an out of place keystone.

Masonic representation of the Royal Arch featuring the Ark of the Covenant by Laurence Dermott (1783)

An image similar to this one was illustrated within a book titled The Lost Secrets of The Sacred Ark by Laurence Gardner

Sharing because anon remembers the discussions regarding keystone and SES. This image just struck anon as being odd and definitely symbolic in nature.