My favorite part of fursonas is taking RL features I don't like so much– stuff that's embarrassing, stuff that makes me feel ugly– and deciding, fuck it, I'm doing this on purpose. I'm going to celebrate this part of me. I can make things fantastical or sparkledogesque, I can remix them to fit an animal/furry concept. But I will make them a design element I enjoy.
I don't know if I'd call this body positivity exactly but it sure has made me enjoy my fursonas a lot.