People of Groupthink: Which dress is prettier?

I am in my older sibling's wedding this summer. It will be July in an old church that probably doesn't have air conditioning. She told us our dresses have to be chiffon, floor length and darker purple (plum or eggplant or whatever). I found two dresses that fit the bill and I personally like. Which one do you like better for a summer wedding?

Dress #1:

Dress #2: