Monday’s face-to-face between the two leaders looked markedly different.

Ukrainian President Volodymyr Zelenskyy was certainly hoping that a spot of fashion diplomacy Monday could get U.S. counterpart Donald Trump to help his country reach a peace deal with Russia.

For decades, an independent group, the White House Correspondents’ Association, determined the “pool” rotation, giving different networks and newspapers turns on different days, but in February, the ...