virtual background serves as static picture?

Yes, you can use a static image as a virtual background. However, a virtual background only works when your camera is turned on it cannot replace your video if your camera is disabled. 

If your goal is to display a static image instead of live video, Zoom doesn't currently support using a virtual background with video turned off. Other participants will see your profile picture (if you've set one) when your camera is off, rather than a custom static image.

Yes, a static picture should work if the video is disabled, though the exact option may depend on the platform’s background settings. I’d keep the setup simple, much like evaluating construction company seo services for the right fit rather than adding unnecessary features.