But what kind of products did this apply to? This is hard to tell since shops came and went, sometimes very rapidly (in the early 20th century the majority of shops in nearby Wimbledon failed to reach their first anniversary. Such a situation was certainly not unique). Between the end of the 19th century and the first decade of the 20th century, at least a butcher, a provision merchant and the United Kingdom Tea Company traded from this address. I doubt the mosaic was laid by the latter though. A large company would rather have had its name written by the entrance and the slogan "quality and value" was not one used by "The 'Premier' Tea Merchant of the World."
In any case, the mosaic was attractive, and the message good and applicable to all kinds of businesses. That may explain why the subsequent owners of the premises kept it.
While looking for some information on that property, I came across the case of Herbert Hancock, who in 1908 was the manager of the Battersea Park Road branch of the United Kingdom Tea Company. Hancock was indicted for embezzlement, theft, and falsification of documents. He pleaded guilty to the latter charge, arguing he had falsified the books for fear of losing his job as business was bad, and was tried on the others. Although he was found not guilty on one account, his other crimes were considered serious enough to sentence him to six months' hard labour. The edited minutes of the case can be seen here (it starts towards the bottom of the page), here, and here.
Location: Battersea Park Road / Picture taken in March 2012