Every June, the giant video game images adorning the walls of the Hotel Figueroa in LA are one of the stars of E3. I'd always thought they were just enormous posters, but nope, turns out they're actually painted by hand.
Many of the more recent ads have been done by a company/group of artists called Walldogs, who specialize in creating huge advertisement murals. Here are some shots of their work for this year's E3, when the Figueroa was done up in Battlefront II images:
See how Darth Maul's face is missing?
And here's the finished article:
To give you an idea of how painstaking this work can be, but also how cool it looks when it all comes together, here's an old timelapse video showing Walldogs' painting of Skyrim's ad for Bethesda in 2011:
And here's an interview with Bloomberg from 2014, where you can learn more about how the work is done, and the advantages hand-painting such an enormous space has over just printing huge posters: