The building in the picture is Palazzo Braschi in Rome, the headquarters of the Fascist Party Federation (the local one, not the national Party headquarters).
It was not always covered up like that; this set-up was displayed for the 1934 elections, in which Italians were called to vote either for or against the Fascist representative’s list.
The “SI SI…” lettering (meaning “Yes Yes…”) was 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 “No” to a single list of candidates presented by the Duce himself.
The voting procedure used two ballots and two envelopes; the yes ballot was in the colors of the Italian flag with fascist symbols, while the no ballot was a white sheet.
The voter had to place the ballots in envelopes, put his chosen ballot in the ballot box and return the discarded one to the voting supervisors, de facto allowing them to check what each person had voted.
The list put forward was ultimately approved by 99.84% of voters. The overwhelming majority provoked Benito Mussolini to dub the election the “second referendum of Fascism”.
When Mussolini promised a new world order for Italy, he set out to give Rome a Fascist façade. In Rome, the capital of the “fascist empire”, Mussolini’s grand scheme was to transform the city with propagandistic buildings and urban stages whose look and feel would broadcast his achievements and objectives.
(This was exactly what the Roman emperors and the popes of the Catholic church had done for centuries, of course; without the inflated egos of so many past rulers).
Architects in the 1920s and ‘30s took their cues from the forms of classical Roman buildings, but whereas the enormous structures of imperial Rome have ornate details and rounded edges that give them a certain Mediterranean warmth, fascist buildings were Teutonic blocks of unrelieved travertine, which made them cold and forbidding.