Yeah I think that Otho was just moving some clothes out of the way to get to showing Delia the wedding dress. When I was little, I thought they could see her in the closet.
Actually he can sense that they are there... remember that he thought that he saw someone running when Adam went to lock the attic and he thought that he felt Adam run past him when they were going check the attic to see if it was open. Plus the hand-book also says that only some people can see ghosts... maybe he is one of the people that can see them.
nooo.
Otho CAN'T see Barbara OR the clothes.
If he could see her clothes, then he would be able to see Adam and Barbara's clothes when they are just walking around the house.
It's just a mistake from the movie, he should have just seen right through them.
So, just a slip-up.
I can't believe everyone has got this wrong. He doesn't see her or her dress- but at the same time this is not a mistake. There were other clothes hanging up behind her, which he moved out the way in order to get to the wedding clothes.