Uh-oh, there is someone who are walking to you wearing same prom dress as you; if you are beautiful than her, it’s no big deal, but if you don’t have confident, we should do something to solve this issues perfect when it happens to you.
First, like your dress as before, it is still beautiful (in fact it did for both of you like it); don’t let it ruin your night. Try to compliment the other girl with “Hey, we have same taste! We both awesome” or something similar; ask to pose for photo with the girl, upload it on Instagram or Facebook, that’s so cool!
To me it’s really awkward, if I can, I will try to pretend not find it. If you feel embarrassed this twin-twin situation, do a bit of styling with the stuff you have at hand, change the shape of the dress by twist it, pin it up; Accessorize it with jewelry, belt ,scarf; and even wear T-shirt as underwear for the prom dresses, you will sparkle everybody on the party.