Unsure of the meaning of the word 'flanker' in this particular context, I attempted to use t'Internet. Official definitions (military and sport) were clearly not a match.
I eventually found this excellent and apposite entry at the bottom of an entry in the otherwise-murky Urban Dictionary (I don't recommend it).
Alas before I got to this useful definition I was subjected to some fairly colourful definitions and contexts. To save you from seeing what I now cannot unsee, here's an extract of the clean and useful part.
From the world of commercial
perfumery: When a particular fragrance, masculine or feminine, has been a huge success, its makers will often try to capitalize on its success by creating "spinoff"
fragrances. These "spinoffs", called flankers, might be similar to the original olfactorily, but with a different spin or variation put on it. "Light" versions, "sport" versions, "
veil" versions are common types of flanker.
Traditional
SHALIMAR perfume seems heavy and musky to a whole new generation of Millennial women accustomed to
fragrances which smell detergent, aquatic and ultra "clean". With this in mind, the company's house,
GUERLAIN OF PARIS, has launched a new flanker: a much lighter version of the classic 1925 sexbomb, pruned of its muskier elements, called simply SHALIMAR LIGHT.