Sounds like Bun chose a bad logo then. They're not going to own the concept of a bao bun with a face.

What about the concept of a window? Can anyone own that? Or, a cat octopus? How about a discarded piece of fruit?

There is nothing distinct about a window or piece of fruit. Obviously if you made an operating system called Windows and used a window as a logo that would be trademark violation, but there's nothing stopping me from opening John's Windows with the logo being a window.

Sure, a trivial strawman example.

But then, if you made not an OS but rather say, a search engine called “pane.io” and used a logo of a 4 pane window of different colors ?

I am open to being wrong here but I doubt it would have gone smoothly.

Who cares? It’s not like they’re in a remotely related niche. Nobody’s gonna confuse the two.

The only real similarity is that it's a bao bun with a face, which Bun didn't create the concept of.