For the people saying it's just grass, you are underestimating how much small touches can really add a lot.
I like foliage in a game, it really adds to immersion and realism imho. It's one reason why I was convinced to go with RDR on xbox 360 when I asked a few months ago (I have both last gen consoles and I will fully admit I'm biased towards PS in general.. which is why I have Fallout 3 and vegas on the PS3 but I ended up rebuying Vegas for xbox in hopes it runs better. Skryim I only had a PS3 when I got it so that's my excuse there
).
Honestly, I've heard xbox one is better in small regards to PS4 in this game. And the comparison of intro videos I saw i actually think overall I preferred the xbox's graphics when looking side by side (xbox was darker and I think I tend to prefer darker. IT was worse though in shadows where there was more differentiation in blacks on the PS4 but overall I liked the One's graphics better from that direct comparison).
But, this to me says that even if I had both consoles, PS4 would be the one I would want. Because foliage does add a lot imho. Where as the other things I prefer the One's graphics for I'm not going to notice unless I'm looking side by side.
Sure, if I only had a One I'd get over it. But if I had a choice, more foliage is something that would sway me.