They tried to sweep up the rice between weddings to reuse it and throw it again. But it didnt matter to get all of it up until later just to save time on fully cleaning the whole hall until it would be used as the mess hall later. Which saved even more time since they didn’t need to bring any more for the rice pudding for desert.
There were multiple weddings that day. That was from a prior ceremony for bit players that weren’t important to the story.
They already had the room, catering, and band set up. Why waste the opportunity. Most efficient.
They tried to sweep up the rice between weddings to reuse it and throw it again. But it didnt matter to get all of it up until later just to save time on fully cleaning the whole hall until it would be used as the mess hall later. Which saved even more time since they didn’t need to bring any more for the rice pudding for desert.