Even if you couldn' t tell the difference, knowing there is a difference is plenty ok to reject someone.
I can' t tell just by looking if someone is a religious extremist or not, but if I am told, you can bet your ass I am going to take it into consideration when deciding whether to date him or not. Same goes with everything. It doesn' t matter how stupid it is, if it makes you think "I am not so sure about fucking/dating this person", then it' s ok.
Oh people can tell the difference. I've seen plenty through various sources and they do not look like real vaginas. They really need to stop fooling themselves.