It forced working digital mirror cameras into the cabins of every stock truck in the game.
Players no longer had to physically lean forward to check their mirrors; high-definition camera feeds sat directly in their peripheral vision.
The direct answer to your query is that is a highly popular digital modification ("mod") created by the developer Seogi for the simulation game Euro Truck Simulator 2 (ETS2) .
In rain or dense fog, physical game mirrors often blur or lose clarity. The camera mod provided a consistently illuminated, clear feed, mimicking real-world advanced driving systems.
Rather than utilizing a sloppy, stretched copy-and-paste method, the mod required precise hand-mapping to ensure the digital screens aligned perfectly with the unique geometry of each cabin.