In the eyes of Facebook this is a very strict no no. Do not proceed. Do not pass go. Just don't. They even added a special clause to their policy about it as no nudity at all is permitted on your timeline. This has caused an outrage amongst mothers who do breastfeed as it's a natural and organic process, they are simply feeding their baby. Mothers are arguing that the nudity is not explicit, it is simply natural and many have experienced their images being removed or having their account banned.