i got my bridesmaids dress back...

my main thought with the pashmina/shawl thing (besides covering) was about being warm! i'm really cold blooded, and even though the wedding's in july, it doesn't get much above 60 degrees here.
You look lovely, try a silk wrap, lightweight & silk is a fairly good insulator. The bride did good by you, that is a great dress.
 
The coverup looks cute but you totally don't need it, that dress looks perfect on you, no upper body "issues" i can see. You should thank the bride for picking such cute dresses for her attendants!
 
You look fantastic! I had a similar situation when I got married. The main part of my dress was strapless but I had a gorgeous beaded duster (sheer fabric had one button in front with long arms and then flowed from the back). That helped me a LOT!

But I think a pashmena (sp?) in an ivory / off white or a complimentary blue would look great!