I'm not sure that talking about visual things such as composition is useful. Showing and looking at example images is better.
This is by Shibata_Zeshin.
[/quote]
Wonderful artwork. It could generate a fascinating conversation about composition as a forum thread.
I agree that conversation about composition is seldom meaningful without viewing an image and relating the conversation to it. But viewing images without a conversation, while fun and instructive, doesn't need a forum, and doesn't get to benefit from others' ideas. It's a solo endeavor.
One of the most interesting forum activities I ever moderated was a thing called Critique The Masters. Every week I posted an image of an artwork - a photograph, a painting, a sculpture, whatever - and links to more information about the artwork and artist for those who wanted to know more. Members gave their own critique. Some of them posted an image of their own that they thought had some kinship to it or illustrated some principle in its design. There was a lot of lively back and forth discussion that we all learned from. I am convinced that shared discussion about images is one of the most effective ways to grow in appreciating and creating art.