https://arxiv.org/pdf/1803.04347.pdf
Please see also:
Clues To Your Health Could Be Written All Over Your Face
http://onlinedatingsoundbarrier.blogspot.com.ar/2017/11/clues-to-your-health-could-be-written.html
Compare to:
His / Her face may be swollen due to subclinical hypothyroidism
http://onlinedatingsoundbarrier.blogspot.com.ar/2017/10/his-her-face-may-be-swollen-due-to.html * Normally cycling women versus women using hormonal contraceptive methods.
"Ovulatory cycle and changes in face width: How women can tell when other females are ovulating using clues in their face - and how they may then try to hide their partners from the 'threat' of these fertile ladies (Women's attractiveness changes with estradiol and progesterone across the ovulatory cycle)"
* Her face may be swollen by a pregnancy.
* His / Her face may be swollen due to subclinical hypothyroidism.
* Persons with facial surgery or even worse Photoshopped / altered / retouched images (nose, lips, eyebrows) can introduce bias in the algorithm.
