1940s Product Placement
We think that product placement occurs mostly in current films. Real products with familiar names brings some additional money to movie studios, and advertising for the product.
Often, made-up names were used in older films. But, in this 1949 film, several real - and possibly now gone - US companies are named, especially a Bekins Moving Van. I rented a Bekins van in the 1970s.
Williams works at a Mobil Gas Station which sold MobilGas and MobilOil, real products in the probably fictional Larkspur, Idaho. And, of course, refrigerated Coca Cola is consumed.
E pluribus unum