Published is the design your customers are looking at this minute. It is stamped on a design the moment you publish it, and it stays there until you publish something else, even while you go off and work on a different design entirely.
Editing Mode is the design currently open on the page in the builder. That is where your edits are going. When you are trying a second look, one card carries Published and another carries Editing Mode, which is exactly the point: you can see at a glance what your customers have and what you are working on.
A third mark, Edited, sits beside Editing Mode when the page has moved on from that design's saved copy. Those edits belong to that design and stay with it if you open another one, but they are not in its saved copy until you press Update on it, or save the page as a new design.