Pam (of the great food blog: Zoomie Station) just left a remark that "exotic" features were popular images on the labels. That's certainly true, although the de Young doesn't seem to have too many of those images in its collection. But what's also true is the portrait of California as an earthly paradise - the promised land where lemons and oranges rained down from the trees and the sun's beams illuminated the earth's bounty. The country was suffering the worst drought in recent history, a killer hurricane on the East coast in 1939 and an economic depression. Thoughtful people could see war from both East and Western horizons. So, it's probably no accident that the anonymous artists of these highly colored labels focused on all things "bright and beautiful."
Zoomie Station: http://zoomiestation.blogspot.com/