It refers to Tess Holliday, the "plus-sized model" who was recently on the cover of People magazine. She's developed a bit of a cult following from the Fat Acceptance crowd as a result. http://www.eonline.com/eol_images/Entire_Site/2015420/rs_634x845-150520092802-634.Tess-Holliday-People.jl.052015..jpg