Was in DC at the end of September staying at the Waldorf (Trump’s old hotel), and saw a bunch of black SUVs with this flag in the windshield parked on the curb by an entrance not open to regular traffic. Also saw press there and some folks walking around in military uniforms. An image search suggested it might be Gabon, but that flag didn’t include the seal in the middle.
The seal in the middle might be the president of Gabon’s. It’s a little fuzzed out in your photo, but a possible match.
https://en.m.wikipedia.org/wiki/Flag_of_Gabon#/media/File%3AFlag_of_the_President_of_Gabon.svg
He was visiting towards the end of September.
https://www.cnbcafrica.com/wire/651205/
I think you’re right. I looked at his pic and I’m pretty sure Secret Service escorted him into an elevator we were waiting for.