But it typically does have to do with age:
"The head to body ratio is a little more complex as it changes from a ratio of about one to four for a small child to about one to eight for an adult. A five-year-old is likely to have a head to body ratio of about one to six."
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This pic shows typical human body proportions as we age to maturity:
From
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"
The younger the person, the bigger the head is compared to the body."
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Finally, we have this pic:
from
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Jen has a child's proportions.
I read an article a few years ago about how child p investigators determined if a subject was a child. One thing they used was head-to-body ratio. I can't find it, so treat that as anecdotal.
"child p" because f95zone censored the real term
Ooh, we're talking science! That sounds like something fun to consider ...
So, your references are very good, I feel.
Though, we might want to revisit some measurements for this discussion as a sanity-check on our assumptions ...
I tend to use the following MrDots composition as a reference for comparative 3D model proportions when trying to create DMD fanart:
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To me, after getting the facial structure and basic body shapes down, the models won't look reasonably convincing unless their relative head vs torso vs legs proportions are closely aligned to MrDots' own "reference" shots AND their relative sizes against other characters fall in line. There is also consideration of proportions with their environments/props, but that's not important to this discussion.
Here's an example of how I sized up and set relative proportions for Melody and D models, where their values were based on a gallery picture from the Melody game with the characters posing together on a beach:
https://f95zone.to/threads/dmd-dating-my-daughter-art-assets-thread.4306/page-13#post-1763896
By that reference, I'm merely attempting to establish that - my lack of skill aside - I do care about learning about the proportions of these characters when it comes to reproducing them via fanart. And, I make measurements from reference images to help that learning process along.
That said ...
Using a photo editing program and roughly rotating+resizing a basic rectangle over the head and upper torso areas of D, Elena and Jennifer respectively, I measured:
D: 125 x 217 px (head), 260 x 330 px (upper torso)
Elena: 120 x 205 px (head), 230 x 340 px (upper torso)
Jennifer: 130 x 215 px (head), 250 x 340 px (upper torso)
If we take a basic ratio of
areas for (head : torso), we get:
D: (1 : 3.16)
Elena: (1 : 3.17)
Jennifer: (1 : 3.04)
If we go by
heights alone, the ratios for (head : torso) look like:
D: (1 : 1.52)
Elena: (1 : 1.66)
Jennifer: (1 : 1.58)
The rough numbers above indicate to me that we're not looking at something younger than a petite young adult for Jennifer's model in the game - and again, I actually know a young adult with seemingly the same proportions as Jennifer, so perhaps that colors my viewpoint, too.
Essentially, I've never seen Jennifer's head as abnormally large compared to her body, but that it could still have been a little smaller in the final model to look slightly more to our usual expectations. When I modeled her, I adjusted proportions manually because her head and (moreso) shoulder widths are greater than you might expect for her height. Actually, her head looks even wider because of her big hair, IMHO.