Recently, a blogger for whom I usually hold a lot of respect posted this on his blog, under the guise of scientific data.

This is a person who is normally very aware about social issues, he makes a lot of educational posts combating racism, sexism, and other forms of bigotry, and has a lot of educational scientific posts on his blog as well.

Thin privilege is not considering a disgustingly fat-phobic graphic to be a form of discrimination. Thin privilege is being a respected social justice blog and considering it acceptable to say something like that about your fat peers.