(Spoilers Extended) What should GRRM's GOT cameo be?

GRRM made a cameo as a Pentoshi nobleman in the infamous unaired first pilot of Game of Thrones.

It seems obligatory for him to have some sort of cameo in the series—I can't imagine he won't feature in some background part in Season 8 (since, unless D&D are planning a surprise in episode 6 or 7, he won't be appearing in S7). That leaves us with six episodes in which to find a place to fit a perfect little GRRM cameo.

How should GRRM pop into his own world?