Right now there is seemingly no way to introduce more elements to the Global Styles 'Elements' section. There seems to be a pre-defined list of items such as text, background, button, link, etc. As a developer, we may want to introduce other elements that live across the site and can be styled based on a color palette. For example, right now there is only 'Button' in the elements. Consider a site which has a primary button and secondary button. If we expose the Elements section to plugins / themes, those can add a 'Secondary button' element. This secondary button element can get a color based on the palette and then it can be styled properly throughout a website.