Keep in mind that, as I was not around 1,000 yrs ago when the artist painted this (honest) I can only give my suppositions based on what I understand of both iconic painting and the methods the artist, writers, troubadours, etc used at the time - to get out the message without getting roasted on the stake.
In addition, besides being an artist, I am a writer - which means I am insatiably nosy and always have my nose in a book - and/or, these days, 'surfing' for any and all interesting studies and information that might shed more LIGHT ;o)
(Ain't this fun?)
Not 300, the symbolism in post 151.