You can ignore the 'total water added' as it really only applies to an all-grain recipe. When you print out the brew steps or with any extract only recipe, you will aim to add a base loading of water, like about 6 liters, add in your extract and then check and adjust your volume to reach 6.56 liters for the boil. Honestly, I don't know how it comes up with that figure for total water in an extract recipe, but it is really meaningless.