No, they don't link out to the veterinarians. Google keeps track of "entities" (people, experts, etc. etc..). So the algorithm/AI understands that this woman is a veterinarian, and that she is apart of that website because she appears on the about page as a part of the organization. And so because the site has veterinarians who are associated with the site, that qualifies them to speak on pets, which is a very strict YMYL niche.Who is getting the links, the vets?
So for example, if you were writing a website on technology and you had Bill Gates write 10 articles and then had him as a part of your organization in the about page, Google would see your site as an authority on technology. I don't know exactly how they confirm that the person is associated with your site, but it unlocks your traffic basically.