I found this advertisement for Johnny Walker whiskey in the Thai newspaper, Lak Mueang (10/16/1940, page 6). It says:

“No matter how fun the dancing is, he’ll still find a chance to come and drink Johnny Walker whiskey to double his enjoyment.”

The woman he is with looks like she is a farang (Westerner) and about double his height. So maybe the subtext here is “drink Johnny Walker and you will have the bravery to ask a tall farang woman to dance.”