Kiwichick,When QF first bought the 747 it was their first aircraft with twin aisles.In those days before business class was thought of they had 4 meal carts which understandably started at each corner of Y/C for the meal service.
When the bean counters started to do what they do best this reduced the crew numbers.This meant that instead of 8 crew in Y/C there was 6 which means that you can't operate 4 meals carts at once because QF carts are operated by 2 crew.
The problem created therefore was where best to allocate the 3 carts.It was decided by the brain surgeons in the office that now you started with 2 at the back of 'E' zone and one at the front which when it got to door L3 did a 'U' turn or horseshoe and went back up the front on the opposite side to which it started.
This means the pax at L3 who had read their menu and could see the meal service and had decided to have chicken or beef or whatever saw the meal cart turn away just when it got to them.To make matters worse it took the crew from the back and the horseshoe crew some time to get to the pax who were watching others eat and were thinking WTF.
Basically it's robbing Peter to pay Paul,if you get what I mean.I hope this clears it up for you.
My question though is if you don't really care why did you ask the question?