So that photo of you was actually true!
Was this during cutscenes? I've seen some flickering/shimmering of textures and shadows on NPCs and Aloy/hair in cutscenes throughout my 7.5 hours so far and all of them have been in cutscenes and all of them in various settings, Frame Gen on, Frame Gen off, DLSS on, DLAA etc. This just seemed like a rendering quirk of the engine, like how dark pockets suddenly get lit up when you zoom in on them (see gif posted earlier).
So predictable. Knew you would use that image
No not cut scene. Gameplay. Was only at certain angles her face would flicker like mad. Weird though as I say I can't reproduce it now as I am further into the game. Maybe area specific somehow.