it was a joke
im not sure why someone would report me for a joke but whatever
Not all jokes come off as such.
And posting pictures of another country in a topic about 1 country in particular is a very easy way to be misinterpreted as possibly bashing on other people's countries, or just trying to cause an argument.
I get that it's an innocent joke, but it's maybe worth avoiding those sorts in future cases. It's not worth the risk of a ban.
And it can very easily rattle some people up. A lot of people get very defensive about their country and their patriotism.