Sagittarius is ruled by the planet Jupiter, named for the god of the heavens and good fortune, and as a result is bestowed with luck, optimism, abundance and ambition. It seems as though Sagittarius can breeze through life with the laid-back sense of power common to those born under a lucky star.
Similarly, the Hermes brand is clearly luxurious and expensive, yet very sporty and laid back. Although sophisticated and high-end, this collection's looks aren't fussy or precious but active and relaxed. The slicked back hair and minimal makeup reflect this posh but easygoing vibe.
Sagittarius is a very sporty sign frequently associated with equestrian pursuits because it is symbolized by the archer. The Hermes brand is well-known for its frequent equestrian references due to the company's own origins as a harness and saddle workshop.
In short, Hermes is too perfect a match for Sagittarius, with its sporty, masculine and expensive aesthetic suited to this sign's personality and associations.