Quick, What's wrong with the stamp above? Tick, tick , tick - BUZZ!
If you knew the answer, you have a rare knowledge of arcane Americana.
Here, look at the stamp below, and you may guess the answer.
Advertising stamp for
5th North American Esperanto Congress, 1957
2nd version
Still stumped? It turns out there are rules about how the US flag can be depicted in photos and images.
According to
this page
When on display, the flag is accorded the place of honor,
always positioned to its own right. Place it to the speaker's right,
the audience's left, in a staging area or sanctuary.
Other flags should be to the speaker's left.
If you didn't know that, don't feel bad, neither did the designers of the stamp, in Spain (that's where most of the Esperanto labels were produced then -
I've no idea why - cheaper?)
So they printed it as shown at the top of this page, with the flag on the right, and blithely sent it on to the esperantists in the US to be distributed in advance of the 5th North American Esperanto Congress, in 1957.
Fortunately, someone on the US end knew the rules, and disaster was averted.