Really makes me feel immersed in the Japanese language. This is a common problem with Duolingo- no matter what language you study, the material just feels American 
And before you ask, no, I did not pay for the subscription, they randomly gave me three free days of Plus, or Super, or whatever it is. Imagine paying for Duolingo 
The most American thing isn’t that the flag (it looks more like Liberian as pointed out other comments lol) but the flagpole at average post office for no reason
I assume most commenters fixated on the design of the flag itself because they’re Americans who are used to seeing flag poles in front of post offices, but I meant the whole thing, flagpole and blue mailbox and all. Besides, with the design of the mailbox I think it’s obvious it’s intended to be a simplified US flag