This is a screenshot i took when playing Horizon. I remember people calling her ugly back then too, but I think she always looked pretty.
The pictures in the OP dont do her character model justice. It's a first person FOV shot so it looks a bit weird. She looks fine in other shots.
I think what they have done here is gone back to her original character model. This is from the very first reveal of Horizon Zero Dawn at E3 2015.
I am not a fan of devs making female characters look ugly to model them after average looking women so as to not set unrealistic expectations. ND is especially guilty of it with the awful fucking model of Abby, making Chloe look ugly, and doing their hardest to make Ellie and Dina look mediocre. All the while making Drake look like a supermodel.
But this doesnt seem to be the case here. I think they just want her to look like her original model. I actually liked her portrayal in Horizon. She is considered very bangable in the world of Horizon. Every man she meets falls in love with her. The king tries to fuck her. Her sexuality isnt exploited but it isnt hidden away either like it is in most games where women are treated like men with tits.
She is still very feminine unlike Abby who looks like a man.