I don't think the pictures we are seeing in this review reflect clearly on either screen.
That being said, I do see what both sides are talking about. The yellows are clearly better on the iPad, but it does appear to have some over-saturation (btw over-saturation means the colors bleed into each other, not that they are brighter or more vivid than natural) that you can see in a couple of flower photos. My question would be though - is what I'm seeing color bleed or a poorly set contrast/brightness, or related to the cameras?
The pictures of the barn look better on the iPad to me. The pictures of the adjacent butterfly look better on the iPad in detail and color. The Nexus - well, I don't know what those butterflies look like in real life, but the yellow flowers are atrociously colored. They are practically orange. Same with the yellow flowers on down the page, though they are the worst in the butterfly picture.
Blues seem to be the other way around in some of these pictures, but not in terms of color, in terms of detail. I'm thinking the blues may actually be over-saturated in the true sense of the word, but I have to wonder about the other contributions to the picture unrelated to screen quality - were they adjusted right? What about the camera? What about the reproduction process that puts them in the article?
Is my screen going to see these images differently than someone else's?
I don't think we as readers can really tell what's going on here. I will say one thing, yellow color on screens is one of my "pet peeves" so I know which screen I like better, and that's the iPad. I'm sick of orang-ish yellows, I tell you! Sick of them!