A Martian visiting my church would conclude that we worship wood grain and green leaves. A co-worshiper likened it to a worship space for gnostics: with nothing to fasten the eye on, the focus must be directed to the Idea, the Abstract.
We rent the space from the Seventh-Day Adventists, who would be well out on the bell curve of no-representations-in-sanctuary. Very 19th C, very extreme Protestantism.
I'm not sure what I would put up if I had the run of the place. But contemplating wood grain and artificial plants no longer does it for me.