"Slopes" could be because of the angle from the top front to the back. It just sort of slopes down instead of having an abrupt hole where your leg sticks out the top. My guess is they're like outdoor slippers - sort of what Gary T. said. You've back in the campsite after a hard day of hiking, your feet are tired and sweaty, and you just easy them into these shoes. Your feet say "Ah - sweet relief," you tell them to shut up and then go collect firewood. They look quite comfy.