Populate multiple select #333

Hi,
I serialized a form to be able to reload it when needed.
All the single select are repopulated, but not the multiple select, even if the $scope is populated.
Here is a plunker with my issue : http://plnkr.co/edit/vL9L2XWeziTPuX4KxwmP?p=preview (select people in the first input then click "copy selected people")

EDIT : Better example here : http://plnkr.co/edit/vL9L2XWeziTPuX4KxwmP?p=preview