Actually, the dress Laura wears in the bedroom is similar to the one in the dress shop, but still not the same. It appears as though instead of having two identical dresses, production just found two dresses that, from a distance, look alike. Tina's bedroom dress is totally different, however.
And it's been bothering me as well that both Julias pick a different dress to become Mrs. Robbie Hart - because she doesn't say, "This is the dress I'm going to marry Glen in," or something like that, she says, "This is the dress I was meant to get married in," and he even says she looks beautiful... Maybe it's the whole superstition "see the bride before the wedding" thing, but still.
"It's not for sissies, contrary to popular belief." - Tommy Tune, on musical theatre.
My avatar: Yummy, no?