Is Tess Holliday’s Cosmo cover glorifying obesity?

This month, Cosmopolitan Magazine shocked many by putting plus size model, Tess Holliday on its cover. Previously, Cosmo girls were only known to be skinny, tall and slightly curvaceous.  Tess, on the other hand, is overweight and laden with tattoos.  Why did Cosmo choose to veer so far away from its typical cover this month?