I heard an interesting concept today but it was unfortunately second hand information.
The basic rundown was that the female breast and more specifically the nipples can be used to find proportions and perspective. There was also the mention of positive and negative spaces being used in the concept. Unfortunately like I said it was secondhand so it wasn’t very clear. I was hoping that somebody here we recognize and be able to explain this concept to me more clearly. Very vague I know but hopefully somebody knows what I’m talking about.