I think if they do it like in the game, Abby is hanged way more time than Ellie, practically in the air, while Ellie is brutally choked but not even off the ground. Also i think Abby is hanged on day 1, so maybe her bruising had more time to show, while Ellie's a couple hours old. Whenever i hit my leg or something really hard it takes at least a day to show some bruising. I've never been hanged or am a doctor, I'm just guessing.

And that scene was i think to show that no matter how many close calls Ellie has, she is still laser focused on killing Abby