yep, I think you got it just about covered, although one might be an older style nappy which may explain the difference, and I really cant remember what I changed!!
Now the day nappies have a longer booster with a small one under, which can be swivelled to the front or the middle depending upon if you are wee catching for a boy or girl
Night nappies have 2 big boosters, joined at the top, plus a wool backed small booster which works in the same way as the day small booster. The lower 'big' booster also has Zorb inside it.
The day nappies have an inner layer through the wet zone, unless they are a print fabric, in which case they are a complete full inner layer of bamboo fleece
Night nappies have a thicker inner layer through the wet zone, made from Zorb