Attraction is based on looks. If it looks like a girl and you're straight, you'll be attracted to it, even if it has a penis.
That's why I don't understand the appeal of reverse traps. Why the hell would you be attracted to something that looks like a man? The only explanation I can think is that you subconsciously love manly men but you're too afraid to love a real one, because you know, it has a penis and stuff, that would be gay. So instead you go for reverse traps, which have boobs and vagoo, so you can satisfy your desire for men without feeling guilty.