Yup, it looks like the new watermark is now '(copyright symbol) 2015' as was originally suggested, which doesn't identify photos as being from FF anymore.
A dislike button showing up in place of the like is strange though, I noted it myself. People should be only able to remove the likes that they've made themselves, another bug I guess.
Edit: Clicking dislike seems to just turn it into a like button, which can then be clicked to give a like.
9 years