It aims to promote home produced goods or at least British Empire produced goods in order to help the domestic economy. A familiar theme even today.
And the article below, also from Good Housekeeping, gives an interesting account of the financial arrangements of an ‘average family’ in the late twenties
It is interesting to note that the weekly wage of 16 shillings paid to the house-maid is only sixpence short of the cost of the grocery bill! How times have changed!