The magazine advertisement might be showing a southern California desert scene. The artist was Jon Whitcomb, better known in later years for illustrations of women. The 1939 street scene by Ansel Adams, better known for his landscape photography, shows a Los Angeles Cadillac dealer in the distance.
Learn more about Jon Whitcomb at http://www.americanartarchives.com/whitcomb,j.htm .
Ad image: General Motors Corporation via http://www.carstyling.ru/en/entry/Cadillac_Advertising_Art_by_Jon_Whitcomb_1938_40/images/7914/ .
Dealer image: Los Angeles Public Library, http://jpg1.lapl.org/00085/00085730.jpg, via http://www.whatwasthere.com/browse.aspx#!/ll/34.0670623779297,-118.385772705078/id/4005/info/details/zoom/14/ .