It’s an advice for aspiring actors, not for artists, but it applies anyway.
Bryan Cranston is an actor, he played the main character in Breaking Bad. What he says is that you should do your job, as you can, and everything else is out of your control, so you should not even think about it.
His advice reminds me of what Elizabeth Gilbert said, that you should stubbornly continue making your art, even if people ignore or hate what you create.
When you are just starting out, it’s difficult to get noticed. For months no one may even know you exist, and no one buys your designs. Wait it out. Create more designs until, one day, one of them sells. It might be the one you expect the least.