>>4496234In the context of hentai, a milf is essentially a mother as seen from the point of view of a newborn child: a massive body whose focal points are the breasts (the only thing a newborn can properly interact with at their age and a source of satisfaction) and whose smile is always available (because smiling is one of the first things a baby can do socially).
Notice here
>>4498906 for instance, in a lot of works the head is smaller, because from the point of view of a breastfeeding child, it's too far both physically and mentally (the complete intricacies of facial expression are lost on a child).
In 3DPD porn there are a million of variables that interfere with this depiction, such as how the girl looks, her direction or agency on the whole scene (how she poses, what she says), what all participants think of it, etc. I like to think of drawn porn as the most direct link to an artist's own fantasies, which in turn makes it a nice way to analize how concepts, such as the milf, materialize into it with the least amount of "noise" possible. In the end, an hentai milf partly embodies the first time a child feels the pleasure of his needs (hunger) being satisfied, and her proportions harken back to this time, present in mostly every man's life.
Yes, this comes from reading a lot of psychoanalysis and a lot of porn. It's an hypothesis. I'd post a relevant picture but I'm afraid nobody has done porn of Sigmund Freud and Melanie Klein.
