https://theconservativetreehouse.com/2019/06/22/conspicuous-messaging-kim-jong-un-receives-letter-of-excellent-content-from-president-trump/#more-165374
North Korea state-run news agency is reporting on a letter from U.S. President Trump to North Korean Chairman Kim Jong-Un. In an interesting aspect to the media report, KCNA releases a picture of Chairman Kim reading the letter.
On the hostage dynamic…. last week the hostage taker (Chairman Xi), finally positioned the public optics of Chairman Kim as the hostage; and indicated a likelihood Beijing would negotiate terms for release (better trade deal) with President Trump. Therefore the rescuer (Trump) now communicates with the hostage (Kim) against an entirely different geopolitical background.
Additionally, both President Trump and Chairman Kim know the picture will be analyzed by high-tech software (Beijing, China and Russia) and the content is easily discoverable. The message itself, as well as the answer to the message (from Kim), is likely in the picture. [Note: the White Shirt, business office, is part of the reply].