Seriously, other than guys in drag, I have never seen an actual human (read: non-fat) feel the need to cover up their insecurities by calling themselves 'princess'.   That explains why they call themselves "fierce" and "fabulous" on Tumblr.  The only other people who do that are guys in drag.  And the guys in drag use it as a way of saying "I look hot and feminine,' whereas Tumblr uses it as a way of saying "I look confident for showing off my fupa, septum piercing and green buzzcut."