Well, they probably think your picture is fake because they doubt you can speed-paint a self portrait that fast. Ha! Just kidding, I know that's not the original. In my opinion some people are too insecure these days and they just make up excuses, shame others, and hang out with similarly insecure people on the internet who blame their insecurity on the same issues when in reality all these people just need to learn to accept themselves, that they will never be perfect, and that they can often change anything about themselves that does bother them. So in other words, some people didn't accept you because of their inability to accept themselves and you presenting yourself as a way that they see as more appealing or more perfect than themselves. What they said is harsh and not really true, and you shouldn't let it get to you too much.