An interesting thing I've noticed with Sanae's design that relates to the history of Suwa Taisha - if you take ZUN's word at face value, then Sanae is the Ohori of Suwa Taisha and also the head of the Suwa clan, IRL this would make her the descendant of Suwa Myojin (In Gensokyo, this would be Kanako) but in reality she's more of a mix of the head priest of Suwa Taisha and the Ohori, i.e. she is a descendant of the god Moreya and also a living god herself.
How does this relate to her design? Every new Ohori used to be sworn in in a ceremony where the head priest makes a Mishaguji possess the Ohori's body - this is how they become gods.
Sanae's divinity of course doesn't rest on that, but she does have a snake in her hair. Apart from representing Kanako (alongside the frog that represents Suwako) I feel like it's also a reference to how Suwa Ohori became gods, as the snake itself is actually alive and very Mishaguji-like, it has autonomy... even though it mostly just hisses at people.
Side note, after a decree was passed abolishing hereditary priesthood, the secret rites of the Moreya clan and the tradition surrounding the Ohori of the Suwa clan were eventually lost.
The current, real life Sanae (who is a grandma and part of the Moreya clan), has no knowledge of the rites and rituals of her clan. Gensokyo Sanae however is explicitly stated to have learned and mastered them at a young age, which is kinda funny.