It's strange that it has been asked twice why it is night everywhere, yet it hasn't been asked how a single picture can be taken of the entire surface of a round world.
To reiterate what (Raven)p.e. said, this is not just one picture, but dozens(perhaps even hundreds) of pictures taken when it is night in their respective locations. So these are different pictures, taken at different times, put together like a puzzle to create an excellent picture of the world at night. Nothing mysterious about that