This group picture could be from a Northern Area & State Command Meeting, but is more likely an Annual Convention.
On the back it is written:
Gladys M. Walker
3520 Sierra Vista Ave
Apparently, Mrs. Walker was a longtime member in Southern California – which lends credibility to the idea that it may be an Annual Convention. If it is indeed an annual convention, it could be anywhere from 1931 to the 1940s.