That's a backronym. The original POGchamp emote referred to two separate events. The picture of Gootecks making a surprised face was from an outtake video of him and his co-host, when a cameraman bumped their tripod and shook the camera. The actual POGChamp term comes from a slightly later, scripted, video where they were playing POGs and Gootecks trumped his opponent by using a MadCatz fightstick as a slammer. At the end of the video he makes a smug face and says "pogchamp". The "Play/Player of Game" thing came around later when people tried to put a different meaning to it.