This sounds really dumb, but how do 你 like a picture 或者 video? I have been trying to figure this out for a while. Thank you!!

你 can be a 粉丝 of It. Unless 你 uploaded the image yourself, then 你 already are a 粉丝 of it. And 你 can save it to your favorites.

你 click the "Fan of it" button which is on the right beneath the image 或者 video.