The metaphor is this picture of our dear Leader watching the solar eclipse:
We are not supposed to look directly at the sun, but our Dear Leader does. Thus, either he has never bothered to learn that rule or he believes that it is Fake News or he knows the rule, but decided that looking manly and daring and foolhardy is more important than preserving his retinas.
Those three possibilities are the ones journalists frequently use to try to explain Trump's behavior: willful ignorance, defining what he does not like as fake and produced by his enemies, and running on the emotional gases of manly stereotypes while giving his finger to the Democrats and the world at large (never mind the costs).
This is the person who decides when the nuclear button should be pressed.