I wish he went a little more into the microdot stuff and tried a little more for getting that small size down. Intelligence agencies aren't the only ones who use microdots/micro print so there should be information out there.
As a note, youtube seems to have changed something with metadata recently so when lemmy instances not based in the US populate, you only get a generic bit about what youtube is in the local to the instance language, as opposed the the video description. https://yiffit.net/post/11706373