Soundtrack image #18's source found?

I just recently learned of the hidden soundtrack images for FEZ. As a big Myst fan, I immedately recoginzed #10 as the D'ni numeral "6" from Riven, a game in the Myst series. But I also immedately noticed that #18 - the smily face - is somewhat related to Myst as well. Not in the games themselves, but in it's creators. This face is the icon used by Robyn Miller, the Co-creator of Myst and Riven. In fact, he still uses this smily face as his internet avatar on his twitter and other sites

Additionally, Robyn did the music for both Myst and Riven. This could by why his icon is hidden in FEZ's soundtrack.