It's not a major bug but still, there is no reason it should have been like that in the first place.
I've noticed when you turn on Reduced Motion (Parallax), the wallpapers are not scaled larger or zoomed in.
I have reduced motion turn on, the whole 3D parallax FX looks too cheesy to me. Panoramas is work with this reduced motion turned on.
Best example would be to sync this wallpaper and give it shot to see what I mean.
That's because that wallpaper isn't a photo, it's a gradient. Try a photo of someone or thing and you'll see it.
If I really need to show visual examples to explain the things I say to ppl.
The wallpaper is actually composed for iOS6's status bar colour changes.
A) Reduced Motion Turned off Pic 1 & 2
B) Reduced Motion Turned On Pic 3 & 4
Notice the differences with the status bar area that has changed? You can actually see the wallpaper zoomed in for Reduced Motion turned off by the gradients too.
I've noticed when you turn on Reduced Motion (Parallax), the wallpapers are not scaled larger or zoomed in.
Images need to be zoomed in so that the parallax will work. Without zooming in, the parallax will just show nothing but black. I think that someone should find a resolution that is perfect to show the center of an image you are looking for and enough for parallax.
Like I said before, beta 4 or 3 had incredibly zoomed in images for parallax. That is why I said beta 4 or 5 had it fixed.