It's also difficult to tell what that weight actually feels like on that particular machine due to the physics involved. I, for one, have never seen a machine quite like that.
There's quite a significant mechanical advantage there. Compare the distance her hand moves to the vertical distance moved by the weight. The weight she feels is probably no more than 50lb.
She’s rowing 100lb (at least, that’s 2 45lb plates + one other plate) with one arm. Serious muscle right there