Isis was an Egyptian Goddess in ancient religious beliefs who was a "friend" to slaves and sinners regardless of her political role. Rihanna felt the need to to ink this lady unerdneath her boobs... 

I understand the message this piece has to a girl like Rihanna but I also feel like she may have dirtied up a beautiful (borderline flawless) body just to express the way she felt, that moment in London. So now every rapper and random dude are gonna take Rihanna's top off and be like "ehhh," it's kind of like when you would open a Birthday present and it was the cheap (store-brand) version of what you really wanted. -BusterRadio