As it says... when I'm browsing the home page or the Explore page, I don't want to lose my place in the collection, but when I say "see code" I'm done with the project page.
(In fact, it'd be great to have a way to open the project in the editor directly from home, explore, user page, etc., either by putting a tiny clickable picture of an editor inside the project's thumbnail or by putting "open in editor" in a context menu for the thumbnail.)