We prohibited external images in our Content-Security-Policy for privacy and security reasons. As an alternative, we provided a caching image proxy specifically for i.imgur.com. This was configured to allow only discuss.grapheneos.org as the Referrer, effectively preventing hot-linking from other sources.
The markdown used for this was  and it would display the image in users posted threads/comments.
The alternative option is to upload the image yourself to Imgur and then post the link here. The [error](chrome://network-error/-301) you are receiving looks like thischrome://network-error/-301:
https://i.imgur.com/vOHmxBD.jpg
GOS-user On this occasion. Why can't I attach files (screenshot in this case) from the chat response options menu? That would make things so much clearer :( is it reserved for desktop only?
However, due to changes in Imgur's Terms of Service on May 15, 2023, along with their decision to block connections from OVHcloud and remove all anonymously posted adult content, this workaround is no longer effective on many platforms.
other8026 I think the forum is set up to block image uploading, so most people upload to something like Imgur then post a link.