Final answer:
The Eurasia signs in the question are likely a reference to George Orwell's novel, 1984, where they represent the ever-changing alliances and propaganda of the superstates.
Step-by-step explanation:
The Eurasia signs mentioned in your question are likely a reference to George Orwell's novel, 1984. In the novel, three superstates, Oceania, Eurasia, and Eastasia, are constantly at war with each other. The signs represent the ever-changing alliances and propaganda of the superstates. Although the enemy is said to come from Eastasia, the signs in Eurasia may be a deliberate attempt to confuse and manipulate the population.