It's not third-party. A "shell" for the Wiimote that would enable you to play games using traditional controls was planned while the system was still called the Revolution; that shell in the picture never actually existed though, it was just a mock-up by IGN.
Damn i thought it was actually a prototype at some point, thank you for the info. I just happened to find the tiny image saved on one of my old hard drives and wondered why i saved it.