How to change the logo of PWA app

Summary:

I have enabled PWA of my web application and I want to change the logo of my mobile app in the mobile. I believe that the Resources Sample has the different sizes of icons and splashscreens. Does that mean I create my logo similar to the icon sizes of Sample? why d we need so many images of icons and splashscreens when all we need is a single image to replace the standard logo with ours. Also if we create multiple sized images as icons, splashscreens and zip and upload them, how those are going to apply as mobile app