Seeing others with anorexia nervosa vs. "thinspiration" I am just curious about this one:

As far as I know, anorexia nervosa does not affect seeing others, so they don't see others as fat. They are reportedly seeing others in a realistic way. While I don't have experience with AN, it sounds understandable for me.

However, I have heard of "thinspiration", i.e. people showing others their thinness and inspiring others to get thin, too. This reportedly encourages people to continue with losing weight.

Each of those phenomena sound understandable alone. However, I don't understand those two together, maybe I misunderstand something: If they judge other people accurately and only misjudge themself, how can seeing someone utterly this make them wanting to be thinner?

I understand that feelings and rational thinking might be in conflict with each other*, but this is not enough for me to understand those two phenomena together.

*) I have some experience with conflicts between rational thinking and feelings due to emetophobia, so I can think out of bounds of pure rationality.
From my reading, I believe that anorexics can see others in the same way as us or they can also see other anorexics as normal.  It seems that anorexics don't necessarily hallucinate rolls of fat or other shape differences between healthy and overweight or obese people.

Thomas et al. (2012) describes the case of ‘Ms A’, who described herself as having ‘3% of full vision’: she could detect only high contrast, some colour, and large shapes under optimal conditions, but otherwise nothing at all. Her anorexia began at age nine, with obsessive-compulsive disorder predating its onset, and anorexia and depression being formally diagnosed at age 14. When she was first admitted to a residential treatment programme, aged 19, Ms A denied the seriousness of her low body-weight (BMI 15.9) and didn’t manifest the psychological criterion for anorexia,


  intense fear of gaining weight or becoming fat, even though underweight.


Instead, she said that she refused food in order to provide a sense of ‘containment, safety, and control’ through the practice of self-restriction.

Talking about her disturbed body image, Ms A described typical features of anorexia in the sighted, including checking behaviours, body avoidance (e.g. avoiding tight clothing), and comparisons with others. As she put it, ‘I do all of the checking, but without the eyes’. She, like other blind sufferers from anorexia, used tactile body checking – feeling for bony protrusions in face, ribcage, spine, and hips, and assessing how tight her clothes felt.

This might mean that in anorexia, vision and touch lend themselves equally readily to involvement in the kinds of distortions that are characteristic of anorexia: over-generalisation (this part of my thigh looks/feels big, therefore I’m fat), and all-or-nothing thinking (either I can see/feel every rib clearly or I’m fat) (Troscianko, 2012)

With this borne in mind, thinspiration could exacerbate the problem if they compare their bone protrusions with the photos shown.  

References

National Collaborating Centre for Mental Health (UK). Eating Disorders: Core Interventions in the Treatment and Management of Anorexia Nervosa, Bulimia Nervosa and Related Eating Disorders. Leicester (UK): British Psychological Society (UK); 2004. (NICE Clinical Guidelines, No. 9.) Appendix 17, Diagnostic criteria for eating disorders. Available from: https://www.ncbi.nlm.nih.gov/books/NBK49317

Thomas, J. J., Weigel, T. J., Lawton, R. K., Levendusky, P. G., &amp; Becker, A. E. (2012). Cognitive-behavioral treatment of body image disturbance in a congenitally blind patient with anorexia nervosa. American Journal of Psychiatry, 169(1), 16—20.
DOI: 10.1176/appi.ajp.2010.10040555 PMID: 22223010

Troscianko, E. T. (2012). Seeing and (Not) Believing in Anorexia - PsychologyToday
https://www.psychologytoday.com/blog/hunger-artist/201212/seeing-and-not-believing-in-anorexia