Redditor cef2010 posted this pic to /r/gaming, explaining that his dad painted it for a client. The beautiful wall art depicts an orange portal leading to the defunct chamber where GLaDOS awaits you in the PC game Portal 2.
"It was in an office in Las Vegas," cef2010 explains in the comments. "He's an independent artist. Typically he uses airbrush." The user goes on to say that the artist works for an interior design company called Chemical Spaces.