New logo
Hope you don't mind I replaced the logo by another one I've made just right now. It's not the best ever, but at least it's not the loomio's one, so the group is more recognizable now.
For it evokes apps (circle) that we connect together (lines). But maybe it's not obvious :/
I think it's a fine placeholder icon; thanks. :) I don't think we should get attached to any imagery unless we select it through a clear and inclusive decision process.
I agree with @gregorycassel
it is not evoke anything specific - hence it is not much better i am afraid