This is a picture of an ice anchor or abalakov. Holes have been drilled into the ice in a “V” shape. – the holes connect at the “V”. A small rope is then threaded through and tied together. This is what you rappel off. In the picture above, there are two abalakovs, which are then backed up by two ice screws. My partner, who is heavier, usually goes first with the backed up abalakovs. I rappel second (now knowing that the abalakovs will hold - hopefully) and remove the ice screws before I rappel. All that is left is the rope.