The contents of the pot should start to inflate, make bubbles, be coming alive!
Transfer the contents of the pot into a larger container (if not it will overflow). Weigh the existing leaven and add the same weight of warm water, mix well, then the same weight in flour, and mix thoroughly.
You have just done the "2nd refreshing", store it with the lid on loosely to let air to pass, or covered with a damp cloth.