Anyone else had the YouTube site go ugly on RT?

I just went to view a video on YouTube on my SurfaceRT and the interface has turned into some sort of big, blocky thing. Same video has the proper interface on my Windows 8 desktop, using Metro IE.

It was fine a few days ago, I think. Is this some sort of shot at MS in response to laying down the gauntlet about YouTube apps? (I'm pretty sure, I'm joking - I hope I am).

Does anyone else have this and more to the point, does anyone have this other than RT? It would be very curious to know if the new interface is present on anything other than just RT as that would be very odd behaviour from YouTube.