It doesn’t work for me.
Error message is:
An error occurred: Sorry, you can’t embed media elements in a post.
The format for an image also looks very strange
I had to insert 3 "X"s to make the format visible
![Screenshot|690x427]xxx(upload://5UienL9vKhmrlsXUBfo9ebcdt1H.jpeg)
However, I can see the embedded image on the right preview page
There is already a post about this