Thinking about soft chairs in chain bookstores reminded me that the first photo I saw of Jack was in an SF encyclopedia (still on sale; I don't remember the name) which I picked up and perused at Borders a few months before I discovered this site. It had a small photo of Jack, the first I had ever seen notwithstanding 30-plus years of fandom. Unlike Anderson and Herbert, to name his Sacramento fen friends, and almost all other name SF writers, Vance was never shown on covers, blurbs, etc; at least I never saw it.
My mental conception had been of a gaunt Navarth-like figure. It quickly adjusted to a gruff, non-gaunt Navarth-like figure.
My favorite depiction of Jack is in the banjo-holding portrait with the ship in the background in the Oakland house. This is done from a 1972 photo that appears in the Cunningham book. In fact, a photo of the portrait is there too.
The very best things about that book are Jack's short but very interesting and revealing autobiographical sketch, and the many great photos of him and family taken over the years.
There is one little photo in the Cunningham group that caught not only Jack, but captured my own mental conception of his appearance, both before and after I ever saw a picture of him or met him. It's the one with Schulz and Terry Dowling; take a look, perhaps you'll see what I mean.