Women do this in my building's food court as well. However, we have different soups every day and they have little condiment cups next to the soup for this specific purpose. The soup is placed so that it is in between 3 different stands where they make your food to order and you have to wait 3-5 minutes. I think they are trying to tempt you into trying the soup so that if you like it you will buy a bowl. There's always 4-6 women roaming around with these cups while they wait for their panini to be warmed up.