if he's really a good friend spend and waste a little time liking the photo without any whines.
consider it a favor. You have the choice to say no and yes.
if it hurts your liver then don't like the photo so you won't rant. otherwise, ignore and worse is block that person.
if someone will ask me to like something, i would say "sorry no. i don't like it." (why should i? if i don't like a thing don't force me to like it) LOL