What the...?

So there I was, strolling across the Serpentine bridge and I was faced with this thing. There have been a few articles in the papers about it. I was baffled and don't get it. Neither did my bro'-in-law. But perhaps thats the point. We thought it is doing something tricky with perspective and at no point can you see the flat plane on the top. 

The temporary pavilion at the Serpentine gallery on the other hand is really good and interesting.

But what do I know?