Well, well, well, what a fountain of feedback. Thanks to you all.
Tony et al: you might be right, it could be the size of the supporting piece that's wrong. I'll have to experiment with that.
John: I am very happy that this is giving you ideas. Let's inspire each other! The more, the better.
Pete: I'll see what I can do. I have a few more pieces coming towards finish now, so another photo session will be coming up soon anyway.
The base is made from one piece of cherry, that's true. The dish is sycamore, though. So I am afraid I have to disappoint you, it's not from one piece.
I still think that the dish should be about 1-2 inches wider, and that would bring the whole thing into balance (pun intended). I'll probably play around with it for a while, if I can find the time amongst all the other things I am playing around with at the moment.