https://upload.wikimedia.org/wikipedia/commons/5/5a/Seal_of_Detroit_(B%26W).svg
That’s a fail. You wanted:
(click “more details” when viewing the image in Wikipedia, then pick one of the PNG file links)
testing
This is a direct link to an SVG
https://upload.wikimedia.org/wikipedia/commons/c/cf/Discourse_logo.svg
This is the Wikimedia Commons page referring for the same SVG, which embeds a .png preview, which is what’s visible.
Looks like Discourse doesn’t display bare SVGs. I read someplace this may be nothing more than an admin configuration item (that isn’t enabled by default).
Another bare SVG from another source
https://dev.w3.org/SVG/tools/svgweb/samples/svg-files/Steps.svg
I tried several different photos, from several different sites, all to no avail. I’m done. For now at least. 
Make sure the link ends with .png or .jpg, and it’ll work. There are some additional cases that will work as well, but those aren’t guaranteed across all sites.
This files ends in jpg.
.
I keep getting this message:
Sorry, you can’t embed media items in a post.
That’s because you’re using unsupported media types. Try a JPG or PNG, rather than the SVG files you seem to want.
SVG (scalable vector graphics) are very popular with Wikimedia web sites (Wikipedia, Commons, Wiktionary) because you can change their resolutions without losing quality. Unfortunately they are neither popular nor well-supported in many places so I’m not shocked that Discourse doesn’t work well with them.
I could have sworn that I tried just about every photo example I could on the internet, including jpeg and so forth.
Anyways, all I wanted to do was to add the above Great Seal of the City of Detroit to the following link: here, on these boards.
Now, if someone wants to do that for me, that would be greatly appreciated .
Are you trying to embed a photo directly in a post? Because we can’t do that, we can only embed links to photos that are hosted elsewhere.
Also, if you want the photo to display in a post, you have to have the link on a line all by itself, otherwise you will see the link in the post instead of the photo.
Yup. Either right-click the online phone and choose “copy link” instead of simply “copy”, or right-click the photo and copy it, then paste it into the address bar (which should post the link to the photo) and copy that, then paste that into the post you are making. I don’t think it’s an unsupported file type that gives the error about imbedding a media item; if it doesn’t recognize it as a supported media item at all it will just post as a bare link rather than trying to imbed it.
Also, if the link doesn’t end in an actual photo file extension (.gif, .jpg, .png, and so on) then it might not work. It might, but there’s a good chance it won’t. And even links that end in a proper extension might also fail if there is something weird in the address that formats strangely in Discourse. I’ve posted links that work fine in my browser, have a valid extension, and yet Discourse interprets something as a line break or whatever and it screws the whole thing up. (When that happens I look for an alternate photo to use.)
@Jim_B, what if you take my previous post and quote it, then remove everything except for the Wiki airplane file name?
Nothing seems to work for me.
That is puzzling. What device do you use?
My test didn’t work…
When I use my PC, the image appears in silhouette like it’s about to load, but it doesn’t. When I use my smartphone, forget about it. I don’t even get to square one. (I am a Charter Member too, you know 
.)
You may want to try the folks over at GQ or whatever it’s called these days. Some pretty smart folks there.
FQ (Factual Questions)
That too.