If I understand your question, we are working on optimizing the SharePoint experience per what device you are on. If on the desktop you are using a modern browser with mouse and keyboard, we optimize for the browser itself and the screen size - aka, this is all about built-in responsive design. And then when a person is on a mobile device, we take a more focused approach to use a native loading of content into an experience that makes sense for touch and tap. We aim for improved performance - instead of loading the whole site/page HTML, we focus on pulling in the content into a UX unique to the mobile experience. We do aim to ensure that experiences across Web (desktop) and mobile are familiar, and optimized for the device and input method.
Best Response confirmed by
Beth Wagner (Occasional Contributor)