Doesn't work at all for me. I tried "pirate flag" and got something ugly and not at all piraty than was then made uglier and essentially blank by the background removal.
Did you try more than once? Happened on my first try too, next few were great
Yes I tried a few other prompt: from what I recall "syndicalist flag" gave a similar result, "hacker emblem" was refused as being potentially NSFW, and "anarchy" was the only one to give an actual result… of a cop emoji! Definitely not working well.