Probably the mechitza loosening towards the end of some weddings, where it isn't just the Kappah who comes to the men's side.
The mechitza actually comes off completely, but that's not a new thing, proposals to keep the mechitza up was actually rejected "because" the tradition was to remove it. Both genders sit on each side of the hall with chosson kallah sitting in front of the women's side. It's probably hard to understand when you don't have the no mingling of the genders level the way mainstream chassidim do.