Change between edit and preview mode

I'm trying to understand what is the approach of edit vs. preview modes.
2 examples:
1. The link plugin starts by showing an input box. After pasting a URL it renders a preview of that URL, but than there's no way to return and edit the link (only delete it and create a new one)
2. The image plugin starts by showing an upload button. Once the image is uploaded you cannot replace it.

Assuming I want to build plugins that allow editing after initial setup what is the right approach to do so? Ideally I'd like to show some popover tool that allows editing different properties of the block.
Is there some example of something like that?

Thanks