Put your cursor on the middle where it days click and drag and do just that... hold the left button down and go for it.
You can change the "symmetry" by clicking on it and the colours in the bottom laft hand corner.
When I tried this on my smart phone I could play around with the images already posted too.... by touching them. Not so on Con's though as his was a screen shot.
But the others I could add to and play with. And on the PC I could click and drag and play with everyones too. (except Con's)
Just keep swimming... just keep swimming.. just keep swimming....