In case you've been using Mediafire to host images so as to embed them, as recommended by me - apologies, but about a week ago Mediafire changed their system (without telling anyone, of course) so that you can't get an embed link anymore. You can get a viewing or download link, but not one for direct display. Thankfully, all my old stored image file Mediafire embed links still work so my art (and yours) will still be visible on AO3 or wherever.
I've been emailing Mediafire's support staff about it, which is how I found out what had happened. They say they changed it to make it easier for people to get download links, i.e. they've prioritised business use over the rest of us. They also say they're working on a fix so we can still get embed links, but no idea when that might eventuate.
If they fix Mediafire and let me know, I'll post about it. Their support desk person said the "view" code could be edited for direct embedding, but I tried and it doesn't work for me - all I can see is the alt text. If you try it and it works, let me know. In the "view" code, you replace "/view/" with "/?" - so "https://www.mediafire.com/view/6j7brgitmw7s8my/arizonaroad.jpg" becomes "https://www.mediafire.com/?6j7brgitmw7s8my/arizonaroad.jpg"
Meanwhile, I've changed to using squidge.org's image hosting to store my images, as that's a dedicated fandom site. It works well - not quite as simple after uploading to locate the embed code as Mediafire used to be, but it's fine. And hopefully safer than a non-fandom site, longer-term.
ETA: Briefly, at squidge.org, after you upload an image you need to click on it to get the details. Below the image, not very obvious, it says "embed codes". After clicking on that, the second option from the top is the one you want, called "image URL". Clicking on that gets a "copy" button.
[Follow-up fix for this is
here]