Hmm, yeah, there is something odd looking about that bit.
But the're no slants in the game (notch said he'll never implement diagonal/smoothing blocks) and the vanishing points do match up, so it must just be Xen being at a funny angle, plus the dark stripe blending into the lower block, to make it look wrong.
No, I played with Barbie and she taught me the valuable lesson that fabulous clothes, shoes and a giant mansion with bold statement decoration and furnishings gets you a hot boyfriend.