Back in 2008, I wrote about this unfortunate chart by the Guardian (link):
The barrel imagery interferes with communicating the data. The green portion looks about the same size as the red portion when the number is four times smaller.
They kind of recognize the distortion and utilize a horizontal cutup instead of following the edge of the barrel. But it doesn't really fix the problem if you look at how 3 percent at the top and at the bottom of the barrel are portrayed.
It's not clear to me why they don't use a simple stacked column chart with horizontal text labels.