iT'S NICE, BUT WITHOUT SEEMING TO BE HEIGHTIST OF FATTIST, i THINK IF YOU ARE SHORT IT COULD SWAMP YOU, AND IF YOU WERE OVERWEIGHT IT COULD LOOK FRUMPY.
Just to add, I think they could vary the hem height - some of the dresses almost touch the ground and will touch the ground if you have to bend the knee for anything. So there should be variation from maybe knee high or just below knee high to just above the ankles (which is what we see in these images).