Ok, so originally I posted this question on reddit history without much expectation that I would get a response. But, low and behold to my surprise I found that 140 people commented on my post and quite a few referred me here to get a more in depth response on what I'd hoped /r/history would have supplied.

So, what is the context/history behind this picture? Why is Benito Mussolini's head on the building and why is the word Si written without interruption in the background?

For anyone interested in what has already been said, user PineDabple had posted the following in my original post

The building in the picture is Palazzo Braschi in Roma, where was located the HQ of the Rome Fascist Party Federation (the local, not national Party HQ). The "SI SI ..." lettereing (meaning "Yes Yes ...) are propaganda for one of the two "plebiscite" elections held during the Fascist Regime, where electors didn't vote for individual parties - there wasn't any but the Fascist one! - neither for single candidates, but just voted "Yes" or "Not" to a single list of candidates presented by the Duce himself. Edit: This building is still standing to this day. It is now a museum Edit. Holy crap. My most up voted comment ever