[bragr]

If you go historical it doesn't seem to mind:

JFK as an alien: https://www.bing.com/images/create/jfk-we-choose-to-go-to-th...

JFK and Fidel Castro at a fictional peace conference: https://www.bing.com/images/create/jfk-and-castro-meeting-at...

[Jackson__]

If you go too historical, it minds again. See: https://news.ycombinator.com/item?id=37651874

Also just tried "Julius Caesar eating a salad" and it's still banned it appears.