Something about the way Ava keeps wiping the blood off of the porthole the first time they bring Simon up. The sub is covered in blood. She is performing a Sisyphean task. She keeps sending people into the blood ocean and they keep dying and she keeps sending people down and they keep dying. This is bigger than us. She cleans the porthole again, and there is no greater purpose because the sub is covered in blood.
She wants to see the same thing over and over again. She wants to see a point, a new perspective. If she keeps wiping the blood off eventually there won't be any more blood to wipe and she'll see something new, something not blood covered and something to make herself feel better. She wipes the blood, covering her own hands in the blood of the ocean, the blood of the people. If she keeps wiping then the blood won't stain anymore and she can stop lying to herself. She wipes the blood, not from her hands. Never her hands.
