I apologize to gemini explorers for the reference image.
I noticed from amfora and portal.mozz.us the image doesn't work.
I just uploaded a png from the upload form in my account page and linked the file as I would do with a normal text page.
=> //<user>.midnight.pub/<file.png>
Tomorrow I'll email m15o if he doesn't see this message before.
Cheers teacup for noticing that! Since it's an image, the easiest would probably be to directly point to https within the link:
=> https://<user>.midnight.pub/<file.png>
That way, gemini browser that support it can open a web browser. Curious to know if anyone knows of another way we could handle images.