Apparently, WhatsApp wants to enable business users to select their own cover images in the future. This option has not yet been released, but there are already indications of it in the background of the beta app for iOS.
Business customers could then just put a cover picture in their profile. Unfortunately, this option does not seem to be planned for private users.
You can see it above, there is then a new camera button in the business settings. This allows you to take a new picture or upload one from the gallery.
Users who then go to the profile will see the new cover image. Of course, this function should not only reach WhatsApp Business for iOS, but also the counterpart for Android.