funnier mean more fun but its a better word to use and it makes more scene to use instead of saying ..."oh that picture is more fun" you can say oh that picture looks funnier"
Him: Kidd twin 1 is funnier than Kidd twin 2.
Her: That doesn't make sense. Haha. Kidd twin 2 is the funniest.
Him: You know I'm right. Funnier sounds better and Kidd twin 1 is!