Thanks for asking the artists anyway!
It's the image at the top left of the website. I think the aspect ratio needs to be 1:1, it seems to have rounded corners when displayed but a circle might look better. Really we just want something to go up in that corner. Sometimes apps will show it as a circle so perhaps rather than a circle we might want something that looks ok displayed as a rounded rectangle and when cut to a circle shape.
I guess for content, something that represents us and that people would vote for. And I guess we would need to be allowed to use it, i.e. we can't use a pepsi logo or anything. Something custom made with permission to use it, or public domain.
I don't know that there would be a minimum or maximum number of peni allowed but I would think avoiding NSFW would be a good idea.
