It is the exactly the same hand symbol Henry VIII used to mark down interesting passages in Bible which he hoped would help him to annul his marriage to Catherine of Aragon.
Delightful! I'd say this manicule is a proto-emoji of sorts.
> Thomas Pynchon parodies this punctuation mark in his novel Gravity's Rainbow by depicting a middle finger, rather than an index finger, pointing at a line of text.
https://en.wikipedia.org/wiki/Index_(typography)