I decided to try and post my first entry for the weekly assignment. I must be doing something wrong, however. I exported from Lightroom with a long edge of 640 pixels and uploaded to Flickr. I then embedded the 640 pixel version into a post in the WA forum. I got an error that it was expecting EXIF data.
Here is what I embedded using [frame.] url [/frame.] (periods added so the frame command wouldn't work)
In fact, maybe the frame code is the problem. That's the only way though that I've found to add an image.