Sharing Images in a Cart

[FairMarket Improve the world]

Hi, For an event I would like to share some images with the group in Trello. When I create a cart as admin I can add photo's or any other files. But as visitor on a public cart I can't. Is it possible that I can share my photo's with the group as a visitor?

Will be greate if any body can help me out:)

Best Regards, Fedor