Images from SpaceWorld 2000. The movie these images are from was just a mock up to show what the GCN is capable of. But Nintendo had been working with the idea of a Zelda game using the realistic graphical style, as proven by this quote from an interview with Shigeru:
"The reason we were able to show you the more realistic looking Zelda battle at Space World 2000 in the summer was because we had been doing some preliminary experiments with the console prior to completing Majora's Mask. That's why that video existed."

Other than the fact that the Link model looks like a girl I would have much preferred this style to cel shading.