I've seen that photo before, I think in the first (and second) edition of Leaf's book back in '78. My recollection - I have not looked at that book in decades - is that the caption said this was taken at the Whisky in LA during the four-night, eight-set gig in Nov '70. Stebbins' FAQ says Brian did the first three set (ie the first night, and the first set of the second night). Those were Brian's first appearances onstage with the guys since Hawaii in '67. The Flame were the opening act and I could swear I've seen a photo of Brian in that shirt with Blondie next to him.
UPDATE: OK, my memory is even foggier than usual. I saw that pic two years ago at a tumblr site and started a thread about it and some others:
http://smileysmile.net/board/index.php?topic=15475.0This was, says Ian at that thread, a showcase for The Flame at the club Big Gus, which Brian, Marilyn and Diane attended.
FURTHER UPDATE: The photo above was discussed here back in 2008, at which time Ian wrote:
"The photos were taken by Earl Leaf and some appeared in the Sept 1970 Teen Magazine (for which publication Earl wrote a column). He states that the BBs threw a party for their "proteges" The Flame. After the Flame played a set (there is a photo of this), Brian, Carl, Bruce and Billy Hinsche jammed with Desi Arnaz Jr on Drums and 16 year old Ricci Martin there too. Also taking part were BBs "womenfolk"-including Marilyn Rovell. Therefore the pics come from sometime in the late summer of 1970 (early Sept at the latest). Probably the party was to celebrate the completion of The Flame's first LP on Brother."
So although Brian took the stage on this occasion, it was a private party, so the Whisky gigs were still Brian's first public performances since Hawaii.