If Sir Richard Branson sent a postcard, it would be this

Sir Richard Branson hands this postcard to an assistant and say, “It needs a stamp.”

This was fun to imagine into existence. I learned the Kármán Line is an attempt to define a boundary between Earth’s atmosphere and outer space. So it seemed as good as any place to originate a postcard, which is today’s ICAD prompt.
Sir Richard Branson is scheduled to launch this 11 July 2021 on the Virgin Galactic as Astronaut 001 among a crew of six others, beating Jeff Bezos by what appears to be ten days.
We will be watching.