Warning: because of how it works, this detector is fairly unreliable and often gives false positives.
EDIT #4: still broken. EDIT #3: appears that reloading the page while in the editor bypasses the see-inside detection for most users... no idea why this doesn't happen to the creator of the project... anyone have any idea? EDIT: seems to be broken :( guess it's time to go back to the drawing board... EDIT #2: I might've fixed it! I don't know... It's very buggy, but it looks like it works! (At least, it did for me when I was testing it...) Interestingly, when you start the project while in the editor and then press "see project page", it gives a false positive. It would be cool if someone could investigate that... Try pressing "see inside" before you start the project, it's still able to tell that you did! XD