It's important to always remember to take this sort of thing with a pinch of salt – it's a bit of fun, not the be all and end all of a game's quality. Take for instance, the image above; it's a nice way of seeing the differences between individual games, but what does one screenshot say about anything? Not a lot when you take into account things like 3D and screen size.
What is interesting is how each of the new versions of the game look different. The HD Collection is clearly better than the original PS2 game and the 3DS version is clearly richer in colour and, in this screenshot, the best looking version of the game.
From the little I played of Snake Eater 3D at Eurogamer, It's different enough to warrant another look despite picking up the HD Collection. The 3D adds a huge amount although the anti-3D crowd are unlikely to be impressed. The HD Collection sees release in Europe at the end of this week, while the 3DS version is coming later in the year.