Add feature so that Spectacle could make selfies.
Spectacle deliberately hides itself from being captured, which seems like the right thing to do. Adding an option to disable this might be possible, but I'd say overloading the UI with yet another option is not worth the benefit. After all, you could just open two instances of Spectacle to get a screenshot of Spectacle – not strictly of itself, though, but except for recursion in the preview area you'd gain nothing.
Wow, there is actually a way Spectacle can take selfies: - Start Spectacle - Press Meta+Print (as often as you want)