I have a Magento 2 extension that I'm trying to upload to Magento Connect. When I drag and drop my zip package for review, a default extension icon is shown. I've searched online (see attached image) and if I understand correctly, there should be a form where I can specify the extension icon, but I can't find it.
Note that Connect is an old system (Magento 1-only), and will be going away entirely I believe in a matter of months. You should be submitting any new listings on the Marketplace, and Marketplace does not have such a bug.