There is not enough information to provide a meaningful
interpretation. The "parent" might be the father or mother, and a
"gown" could be a wedding gown, hospital gown, graduation gown,
nightgown, evening gown, etc. Seeing one's father in an evening
gown would mean something very different from seeing one's mother
in the same dress, and a hospital gown would be very different from
a graduation gown.