One, people should download the high quality video from Gameryside. Game looks absolutely gorgeous, streaming quality doesn't do it justice.
Two, people should take a look at how the game looked like on the PS3 back in 2010. Super fuzzy, dirty, blurry, horribly jagged shadows and vegetation, used dithering instead of true transparencies. All of this is gone in the PS4 game. IQ is pristine. And the framerate was sped up in these trailers, by all accounts in ran terribly, and you can see that in the videos that came with the ICO/SotC collection.
And three, obviously both versions of the game resemble each other since they're still the same game and share the same aesthetic and art design, but it's not just performance and image quality upgrades that are in play here.
Trico has many more feathers, all of them animate, has more whiskers, more fur. It's a much more accomplished character model.
The game also has better lighting, shadowing and is using SSAO. People already posted my gifs, but really in motion this thing is absolutely outstanding.
This game is really astounding... The "Team ICO" games are incredibly well animated, emotional, awe inspiring experiences.