This is a pet topic of mine. It’s a screenshot of an expert on a particular subject live on tv news. The problem is, if you have a bookcase behind you, guess what? Viewers are concentrating more on which books you have - more than what you’re saying.
While this example is from tv news, it’s also relevant to video and also Zoom calls.
I do appreciate that sometimes there may be no alternative, but beware of what’s behind you - and the distraction it may cause!