The highest res photo on that site was 400x300. Quite a bit smaller than even 480i (or 480p) which would be at least 704x480 on a standard 4x3 TV.
Given that, I suspect the actual game looks better than what we're seeing here
However, I doubt it matters to the people that will be buying and playing this..they aren't "hard core" gamers, or "core" gamers (or whatever term people use to describe themselves when they want to be seen as better than the game playing masses .
They're aiming this at kids (or parents/grandparents of kids).
If they do a decent job with the gameplay, and make it accessible to younger kids, I'll probably be buying a copy to play with my daughter (she enjoys Mario Party 8 a lot).