A New Take on an Existing Perfume
A flanker is a new version of an existing perfume. Instead of creating a completely new fragrance from zero, the brand takes an already known perfume and makes a different interpretation of it. The new version usually keeps part of the original DNA, but changes things like the notes, sweetness, freshness, intensity, concentration, or overall character.
Not Always Close to the Original
For example, a fragrance can have an Eau de Parfum, Parfum, Elixir, Intense, Sport, or Summer version. These can all be flankers of the original perfume, but that does not mean they will always smell very similar. Some flankers stay quite close to the original, while others can change the formula so much that they almost feel like a completely different fragrance.
Why Brands Make Them
Brands usually make flankers because the original perfume is already successful and recognizable. This makes it easier to create another fragrance around the same name and DNA while offering something slightly different for a different season, style, or type of user.