I blinked, twice. Yes, it seemed to be true.
Is this evidence of some latent thread of Czech hope, a nostalgic longing for a mythic Slavic past, a yearning for reunification with Československo’s lost little brother, Podkarpatská Rus? Emboldened, perhaps, by Putin’s recent swallowing in a single bite the whole of Crimea, were there Czech irredentists on the march?
The whole thing struck me as maybe satirical, so I went to the internet to find out more. It is true that, prior to 1989, the six stone frames built into the wall that separates Letná hill from the embankments named after Edvard Beneš and Kapitán Otakar Jaroš, were used for socialist propaganda. After the change of regime, they fell into disuse. In 2005, they were again put to use as an outdoor public art gallery named Artwall.
The current exhibition, Verchovina, is by a group of Slovak artists, known as Kassaboys, who hail from Košice (Kassa in Hungarian). The posters act as the ephemera from a fictitious referendum to reunite Czechoslovakia, including Subcarpathia, which was an integral part of the republic in the interwar period 1918-1938. The artists themselves state that the work is a reaction to current events in Ukraine, where an implicitly fictitious referendum in real life has brought Crimea back under Russian rule. And their choice of the series of words: integration, connection, affiliation, annexation serves as a commentary on a possible future for Podkarpatská Rus (and, pars pro toto, of the whole of Ukraine) with regard to the EU.
The original posters show that they were composed by adding the red slogans on the illustrations of a German-language travel brochure of Subcarpathia from the 1930s
You can find out more at the Artwall web site (in Slovak) and in this article of the Aktualně.cz site (in Czech).