Picture of a tweet with the caption: “The International Olympic Committee had to ask fans not to boo the U.S. delegation led by JD Vance and Marco Rubio during the opening ceremony.”
Over a picture of J.D. Vance putting his hand on his chess with a US Paralympic press background
It’s just the union flag, when on ships or land. Union jack is when it appears in the corner of another flag, like on old Canadian flags and current provincial ones, aus, NZ, a bunch in the carribean, etc.
You got me looking. https://en.wikipedia.org/wiki/Union_Jack