That extra step can be reassuring on a piece meant to be worn often. A double latch clasp requires two separate actions to open, reducing the chance of accidental release through built-in redundancy.
Style Notes
The heart symbol's meaning has expanded in an interesting direction, the same form that communicates romantic love between two people reframed as a personal affirmation when worn by one, the self-purchase trend adding a new dimension to the motif that does not compete with its romantic meaning so much as sit alongside it.
Visually Speaking
Often diamond-set, gemstone-set, or engraved, the box clasp has become a design detail in fine jewelry production. The closure becomes a decorative element your gift recipient can use intentionally, rotating it to the front on a necklace rather than keeping it at the back.