It doesn't have a overhanging flush rim all around the inside of the pan where normally it's a moulded section with holes/a rail to carry the flush water all around the pan, it only has a diverter piece at the back of the pan.
They say they are meant to be more hygienic but the 3 I've seen don't flush the whole pan, it misses some of the top/front section and TBH normal rimmed toilets just need cleaned properly